BEIJING (AP) The Latest from the IAAF world championships (all times local):
The sister of 110-meter bronze medalist Aries Merritt has never missed one of his big races.
This time, it couldn't be helped. LaToya Hubbard is donating a kidney to her brother and doctors vetoed her travel plans with surgery scheduled for Sept. 1.
Hubbard said she got up early in Arizona on Friday to watch Merritt win an improbable medal at the world championships. The Olympic champion and world-record holder has been operating at less than 20 percent kidney function for quite some time.
''To see all he's gone through - the pain, the hurt, barely able to get out of bed, barely able to walk. And now, a few months later, he has a medal,'' Hubbard said. ''Every time I see my brother run right now, I get tears in my eyes.''
Danielle Williams won the 100-meter hurdles at the world championships in 12.57 seconds Friday in a final that didn't feature an American in the top three.
The 22-year-old Jamaican held off Cindy Roleder of Germany, who was second in 12.59. Alina Talay took bronze in a Belarus-record 12.66.
Defending champion Brianna Rollins of the United States was fourth in 12.67, 0.01 ahead of European champion Tiffany Porter of Britain.
Sharika Nelvis, who had the fastest time of the season and was a medal contender for the United States, placed last in the final.
Dawn Harper-Nelson, the 2008 Olympic champion, crashed in the semifinals.
Sergei Shubenkov lunged late to win the 110-meter hurdles final in a Russian-record 12.98 seconds at the world championships Friday.
Hansle Parchment of Jamaica took silver in 13.03, edging Olympic champion and world-record holder Aries Merritt of the United States by 0.01.
Merritt, who has a kidney condition that will require a transplant early next week, took the bronze.
Tianna Bartoletta won her second long jump world title, 10 years after her first.
The American took the lead for the first time in the final when she jumped 7.14 meters (23 feet, 5 1/4 inches) with her last attempt.
Shara Proctor of Britain took silver with a best mark of 7.07 (23-2 1/2), and Ivana Spanovic of Serbia was third at 7.01 (23-0).
Bartoletta also won the world title in 2005.
Dutch sprinter Dafne Schippers won the 200 meters in a world championship record of 21.63 seconds on Friday, lunging past Elaine Thompson at the finish line.
Thompson took silver in a personal-best 21.66, just ahead of Jamaican teammate Veronica Campbell-Brown in 21.97.
Ashton Eaton set a world record in the decathlon's 400-meter race, winning his last event of the day in 45.00 seconds.
That gave him 4,703 points overall after five events at the world championships, a lead of 173 over Damian Warner of Canada.
The defending Olympic and world champion opened the competition with a championship decathlon record in the 100 when he won his heat in 10.23 seconds. He maintained his lead through the long jump, shot put and high jump and extended it with a commanding finish in the 400.
Warner is second with 4,530 points and Rico Freimuth of Germany is in third with 4,406.
Eaton and Bill Toomey shared the previous 400 record of 45.68.
The U.S. team encountered some serious obstacles before getting two women into the 100-meter hurdles final.
Dawn Harper-Nelson, the 2008 Olympic gold medalist and silver medalist in London in 2012, crashed over the second hurdle and tumbled into an adjacent lane in the opening semifinal heat. Kendra Harrison was disqualified for a false start in the next race.
Defending champion Brianna Rollins won the third of the semifinal heats and qualified with the fifth-fastest time of 12.71 seconds, becoming the second U.S. woman to qualify. Teammate Sharika Nelvis was second in the opening heat and second overall for the final in 12.59.
Danielle Williams of Jamaica led all qualifiers in a personal-best 12.58.
Dawn Harper-Nelson crashed in the semifinals of the 100-meter hurdles Friday, her trail leg clipping the second hurdle and causing her to tumble out of her lane and come to a stop in front of the third set of barriers.
The 31-year-old Harper-Nelson, who won Olympic gold at the Bird's Nest in 2008 and took silver at the 2012 London Games, entered the world championships as one of the leading medal contenders in the race.
Usain Bolt and the clumsy cameraman returned to the scene of their collision, only this time there was nobody doing backflips.
When they met again Friday, Bolt had just received his gold medal for winning the 200-meter final the previous night - the race that preceded a dramatic collision with a TV cameraman who was filming his celebration from a two-wheel motorized vehicle.
The two-wheeler hit a metal rail on the side of the track and veered right into the back of Bolt. He hit the Jamaican in the legs and both fell backward onto the track. Bolt flipped back onto his feet and, after checking to see if the TV operator was OK, walked away.
Video of the accident went viral, and Bolt said he was OK apart from a few scratches.
On Friday, they shook hands and smiled, much to the amusement of the crowd at the Bird's Nest.
Defending champion Ashton Eaton maintained his lead in the decathlon after four events with 3,643 points at the world championships.
But the American's advantage over Damian Warner of Canada was trimmed to 56 points after Warner had a season best of 2.04 meters (6 feet, 8 1/4 inches) in the high jump. Kurt Felix of Grenada was third.
There is one more event, the 400 meters, on Friday and five more Saturday. Eaton is the 2012 Olympic champion and world-record holder.
American decathlete Trey Hardee has withdrawn from the competition at the world championships because of a lower back injury.
The two-time world champion hurt his back in the long jump Friday morning, clutching at his left side when he stepped out of the pit after a foul on his third attempt. He struggled in the shot put before pulling out of the competition before the high jump.
Hardee won the event in 2009 and '11.
His agent, Paul Doyle, says Hardee is ''undergoing testing at the USATF medical office today to determine the extent of the injury.''
Defending champion Ashton Eaton leads the decathlon after three events with 2,830 points, including a world championship record in the event in the 100 meters.
The world-record holder opened his program Friday by winning the 100 in 10.23 seconds, the fastest time ever recorded in a world championship decathlon. He jumped 7.88 meters (25 feet, 10 1/4 inches) to record the best mark in the long jump and hung onto the lead with the ninth-ranked distance of 14.52 meters (47-7 3/4) in the shot put.
Damian Warner of Canada was in second place with 2,747 points and Rico Freimuth of Germany moved into third with 2,730 after recording the top mark of 15.50 meters (50-10 1/4) in the shot put.
Trey Hardee, a two-time world champion, appeared to injure his back or side in the long jump. After a foul on his third attempt, Hardee clutched at his side when he stepped out of the pit. His best mark of 7.30 (23-11 1/2) had him in ninth place at that point.
Hardee slumped to 26th after the shot put, recording a foul on his first attempt and a mark of 10.20 (33-5 3/4) on his second - his personal best is 15.72 (51-7) - before passing on his last attempt.
There is a 3 1/2-hour break between the shot put and the high jump. The 400 will be the final event of the day.
Defending champion Bohdan Bondarenko and 2013 world championship medalists Mutaz Essa Barshim and Derek Drouin were among the leaders in high jump qualifying at the world championships on Friday.
Nine jumpers cleared 2.31 meters (7 feet, 7 inches) and five more qualified for the final at 2.29 (7-6).
Drouin, the Olympic and world bronze medalist, didn't miss any attempts at five marks, including 2.31 (7-7), while Barshim missed his first attempt at 2.29 (7-6).
Zhang Guowei of China was also faultless to 2.31 (7-7), while Brandon Starc - the youngest brother of Australian cricket star Mitchell Starc - was twice on the verge of elimination, missing his first two attempts at both 2.26 (7-5) and 2.29 (7-6) before clearing those and then clearing a personal-best 2.31 (7-7) on his first attempt.
Olympic silver medalist Erik Kynard of the United States and 2007 world champion Donald Thomas of the Bahamas qualified with marks of 2.29 (7-6), but 2011 world champion Jesse Williams failed to reach the final.
American 100-meter bronze medalist Tori Bowie will not be part of the team's relay pool at world championships this weekend.
In a press release sent Friday, USA Track and Field said athletes were required to participate in a pair of relay camps leading up to the worlds this year. The camps were deemed especially important because of the number of new, inexperienced runners taking part on the team.
Bowie did not attend all the practices, and so she won't be part of the team.
The 400 relay final takes place Saturday and the 1,600 relay is set for Sunday.
The U.S. women sprint relay team has won gold medals at the 2011 worlds and 2012 Olympics and took silver in 2013. But before that, they had trouble with dropped batons and injuries that led to some restructuring of the team's practice and selection process.
As they entered the Bird's Nest, Chinese teammates Liu Hong and Lu Xiuzhi discussed whether they would try to outduel one another down the final stretch.
They didn't, with the more experienced Liu winning the 20-kilometer walk ahead of her younger opponent and giving China its first gold medal of the world championships.
''I think both of us would like to have the gold,'' Liu said. ''We talked about whether we would have a fierce ending, then my little sister said, let's just enter the stadium like this (side by side). So not a very fierce ending.''
Liu and Lu were virtually assured of gold and silver when they came into the stadium together, leading their nearest competitor by more than 20 seconds.
The only question was who would win gold: the veteran Liu, the world-record holder competing in her fourth world championships, or the 21-year-old Lu, competing in her first?
Experienced counted this time, but both were given the same time - 1 hour, 27 minutes, 45 seconds.
Ashton Eaton recorded the best mark in the long jump, following immediately on from his world championship decathlon record in the 100 meters, to lead with 2,070 points after the first two disciplines.
The Olympic and world champion recorded 7.88 meters (25 feet, 10 1/4 inches) with his first jump and didn't improve on that. He ran 10.23 in the opening sprint, the fastest time ever recorded in a world championship decathlon.
Eaton, who holds the world record, didn't compete in a decathlon in 2014 but entered the meet as the favorite.
American teammate Trey Hardee, a two-time world champion, appeared to injure his back or side in the long jump. After a foul on his third attempt, Hardee clutched at his side after leaving the pit. His best mark of 7.30 (23-11 1/2) had him in ninth place with 1,847 points.
Damian Warner of Canada produced a personal-best 7.65 (25-1 1/4) in the long jump to hold on to second place with 1,992 points. Felipe Dos Santos of Brazil was third with 1,913 points following his season-best 7.54 (24-9) in the long jump.
China has won its first gold medal of the world championships with Liu Hong winning in the women's 20-kilometer race walk.
Liu won in 1 hour, 27 minutes, 45 seconds, finishing only steps ahead of teammate Lu Xiuzhi. Lyudmyla Olyanovska of Ukraine won the bronze medal, 28 seconds behind Liu.
Liu, who set the world record in the event in June, has a silver and two bronze medals from the previous three world championships.
Italian teammates Eleonora Giorgi and Elisa Rigaudo were in third place at the mid-point of the race but were both disqualified after receiving three warnings for lifting both feet off the ground at the same time.
Olympic champion Ashton Eaton started the defense of his decathlon world title on Friday by running 10.23 seconds in the 100 meters, a championship record for the 10-discipline event.
Eaton, the decathlon world-record holder, won the last of four heats to collect 1,040 points, holding off Damian Warner of Canada, who picked up 1,020 points for finishing in 10.31.
Rico Freimuth of Germany ran his season-best 10.51 and was followed by Felipe Dos Santos of Brazil in 10.53 and two-time world champion Trey Hardee in 10.56.
The decathletes were also competing in long jump and shot put during the morning session on Day 7.
As expected, Chinese teammates Liu Hong and Lu Xiuzhi were leading at the halfway point of the women's 20-kilometer race walk.
Liu has three medals from the past three world championships, but no gold. She set a world record in the event in June.
Lu has the second-fastest time in the field this year.
Elisa Rigaudo and Eleonora Giorgi, both from Italy, were in a pack of walkers about 25 seconds behind.
They're off and ... walking.
The women's 20-kilometer walk is the first event to get going on Day 7 of the world championships, with China favored to win its first gold medal of the competition.
Liu Hong, who holds the world record in the event, is the one to beat.
In the evening session, there will be four more finals, including the women's 200 meters. The men's 110 hurdles is also on the schedule, along with the women's 100 hurdles and the women's long jump.
The decathlon, with Olympic gold medalist Ashton Eaton as the favorite, will also get started on Friday.