GOLD COAST, Australia (AP) Katie Ledecky grinned and nodded her head, very slightly, in a show of approval as she surveyed the times on the scoreboard for the 800-meter freestyle.
After starting her opening night program with a gold medal in the 200 free at the Pan Pacific championships - her first at that distance in a major international meet - the 17-year-old American finished it off by narrowly missing her own world record in the 800.
It was widely expected that an American woman would win two titles on Thursday. But it was Missy Franklin, a six-time winner at last year's world championships, who had seemed most likely to do that until she hurt her back in practice.
Instead it was Ledecky, the reigning world record-holder in the 400, 800 and 1,500 freestyle, who seized her opportunity, saying she really only wanted to see how she would do competing in the 200-800 combination.
''I'm really looking forward to the rest of the meet,'' Ledecky said. ''This day gives me a lot of confidence. The 200 gave me a lot of confidence for the 800, so just sort of building off each of my swims.''
She was a body-length ahead of world-record pace at one stage but faded slightly to finish in 8 minutes, 11.35 seconds - just outside the world mark of 8:11 she set in June. Lauren Boyle of New Zealand was second in 8:18.87 and Brittany MacLean of Canada was third.
The pain started to set in at the 500-meter mark, Ledecky said, explaining that her shoulders and arms ''got kind of tired.''
''Once I got to the 600 mark, I told myself `I just swam the 200 a little bit ago, I can swim a 200. I can get through this,''' Ledecky said. ''I wasn't really focusing on hitting a certain time, I just wanted to get through the double.''
With no Franklin in the earlier 200 final, Ledecky won in a meet record 1:55.74, ahead of Bronte Barratt of Australia and American teammate Shannon Vreeland.
Franklin, hampered by back spasms that stopped her in practice on Tuesday and kept her in doubt for the meet until the first morning of competition, didn't qualify for the A final of the 200 free. However, she did post the second-fastest time of the night by winning the B final in 1:56.04, and that was enough to earn her a spot at next year's world championships.
''I'm really proud of myself. It has nothing to do with my times, my places,'' Franklin said. ''Just getting out and kind of fighting back against life right now.
''I got out there and raced, and a couple of days ago I didn't think I was going to be able to do that.''
She's planning on swimming the 100 freestyle on Friday, and the 200 backstroke later in the meet.
In the 100 backstroke, an event she won at the last Olympics and world championships, Franklin took bronze behind Australian teammates Emily Seebohm and Belinda Hocking. Franklin was tentative with her start, but Seebohm powered off the wall and was under world-record pace in the first lap before finishing in a meet record 58.84 seconds.
Seebohm, the Olympic silver medalist, was happy to get her first victory over Franklin regardless of the conditions.
''A win is a win,'' Seebohm said. ''She is obviously a strong competitor and, sometimes, you just have to go out and race your competition. It gives me a lot of confidence going forward.''
The Americans also collected gold in the women's 200 butterfly, with Cammile Adams winning in 2:06.61, and Connor Jaeger surged home in the last lap to win the 1,500 in 14:51.79, touching a fraction in front of Ryan Cochrane of Canada and Mack Horton of Australia.
The other men's titles were shared.
Japanese men won two finals, with Ryosyuke Irie beating American teammates Matt Grevers and Ryan Murphy in the 100 backstroke and Daiya Seto winning the 200 butterfly ahead of Leonardo De Dues of Brazil and Tyler Clary of the United States.
Thomas Fraser-Holmes of Australia won the 200 freestyle in 1:45.98, edging Kosuke Hagino of Japan and another Australian, Cameron McEvoy. American teammates Cameron McEvoy and five-time Olympic champion Ryan Lochte were fourth and fifth.
Michael Phelps, the 18-time Olympic gold medalist who is competing in his first international championship since coming out of retirement, is due to start his program in the 100 freestyle on Friday.