KAZAN, Russia (AP) Katie Ledecky just keeps winning at the world swimming championships.
Ryan Lochte is back on top, too, and together he and Ledecky carried the United States to its first two-gold medal night of the eight-day meet Thursday.
Ledecky anchored a 3.04-second comeback victory in the 4x200-meter freestyle relay for her fourth gold. Lochte won a record fourth consecutive title in the 200 individual medley.
''We had a great night,'' Ledecky said. ''We're really getting some momentum and showing what we can do.''
Missy Franklin led off the relay for the Americans, and Leah Smith and Katie McLaughlin kept them within striking distance of Sweden, which was under world-record pace for much of the 16-lap race.
Ledecky dived in and quickly pulled even with Swedish anchor Ida Marko-Varga. The American teenager opened a slight lead at 700 meters and extended it to a body length before powering home in 7 minutes, 45.37 seconds.
''I knew I could bring it home and get this thing done,'' said Ledecky, who climbed out of the pool and into an embrace with her teammates. ''We had a blast out there. We were so relaxed.''
It was the third straight victory in the 4x200 relay for the U.S. at the worlds.
Italy earned silver in 7:48.41. China took bronze in 7:49.10. The Swedes faded to fourth.
Ledecky won the 200 free on Wednesday, to go with victories in the 400 and 1,500 freestyles. She set two world records in the longest distance race for women.
''She's phenomenal. She's a beast,'' Lochte said of his 18-year-old teammate. ''Between my win and her world records, hopefully it got Team USA on a roll.''
Michael Phelps put in his two cents' from half a world away, texting Lochte and urging him to be more of a leader with the U.S. team. Phelps qualified for the worlds but wasn't in Kazan as part of his punishment by USA Swimming for a second drunk-driving arrest. He's competing at the U.S. nationals in Texas this week.
''He's right,'' Lochte said. ''I've got to be the team leader, whether it's in the pool or out of the pool, cheering, getting them going.''
After a fourth-place finish in the 200 free, Lochte made history in the 200 IM. He trailed through the first three legs but came home strong on the freestyle lap and won in 1:55.81.
''That's the coolest thing,'' Lochte said.
He joined Grant Hackett of Australia as four-time champions of their respective events. Hackett once dominated the 1,500 free.
''I'm definitely really humbled,'' Lochte said.
Thiago Pereira of Brazil finished second in 1:56.65, and Wang Shun of China was third in 1:56.81.
It was Lochte's 24th world championships medal - second only to Phelps' career total of 33 - and his 16th gold.
The U.S. has won the event seven consecutive times, starting with Phelps' three titles in 2003, 2005, and 2007. Lochte picked up the mantle with previous victories in 2009, 2011, and 2013.
Lochte kept it low-key after hitting the wall, exchanging a hand clasp with Pereira, who was in the lane next to him. Lochte had just two individual events, although he could be selected for the remaining relays.
Pereira led the backstroke and breaststroke legs before Lochte overtook the Brazilian midway through the final lap.
''I thought I could break 1:56 but I couldn't,'' Pereira said. ''I'm happy with a medal, and right now this is just good training. I'm looking forward because we have a year to go to the Olympics in Rio, in my country.''
Ning Zetao of China led all the way to win the 100 freestyle in a race missing two key competitors. He touched in 47.84 seconds.
''This evening is the night I will never forget,'' Ning said through a translator. ''It is a dream of Asia, of China, to get gold medals in sprint distances, so I will have more confidence to prepare for the Rio Olympic Games.''
Ning swept the 50 and 100 freestyles at last year's Asian Games, becoming the first Asian swimmer to break the 48-second barrier.
Cameron McEvoy of Australia finished second in 47.95.
Federico Grabich of Argentina was third in 48.12, earning his country's first medal at a long-course worlds.
Olympic champion Nathan Adrian of the United States tied for seventh, Vladimir Morozov of Russia was disqualified for a false start in the semifinals, and defending champion James Magnussen of Australia was home with a shoulder injury.
''The Olympics will be completely different,'' Grabich said. ''Magnussen will be swimming, Adrian will be in better form. It will be much, much more difficult.'
Natsumi Hoshi of Japan rallied on the last lap to win the women's 200 butterfly, and Fu Yuanhui of China won the women's 50 backstroke, a non-Olympic event.