Aaron Peirsol lowered his own world record in the 200-meter backstroke Monday, then helped his American teammates set a world mark in the 400 medley relay on the last night of the World Short Course Championships.
Brooke Hanson of Australia won her record sixth gold medal, beating American Amanda Beard in the 200 breaststroke.
The United States won five of 12 finals Monday, giving the Americans 21 victories in 40 events and 41 medals overall. Australia was the only other country with a double-digit total. The Aussies earned 29 medals, including seven gold.
Peirsol's time of 1 minute 50.52 seconds in the backstroke bettered his mark of 1:50.64 set in March at a short course World Cup meet in East Meadow, N.Y. He also won the 100 backstroke.
"I had a pretty good inclination that I could do something like that," said Peirsol, who swept the backstroke events at the Athens Olympics two months ago. "It's so easy when the crowd is behind you."
The team of Peirsol, Brendan Hansen, Ian Crocker and Jason Lezak won the relay by more than five seconds over Australia in 3:25.09, bettering the mark of 3:25.38 set by the University of Texas at the World Cup meet in March. The Aussies finished in 3:29.72. Russia was third.
"Every time we get together, some magic happens," said Lezak, who began the evening with a victory in the 100 freestyle.
Peirsol led off and Hansen put them under world record pace on the breaststroke leg. They fell slightly off record pace during Crocker's butterfly before Lezak brought it home in record time on the freestyle anchor leg.
"Those guys got me going," Peirsol said. "It's just amazing. I'm real tired."
Four world records were set during the five-day meet held in a 25-meter temporary pool at Conseco Fieldhouse.
Hanson broke the gold medal mark she shared with China's Le Jingyi (1993) and American Neil Walker (2000). She won the 200 breaststroke in 2:21.68, ahead of Beard in 2:22.53.
"I've been telling my dad all day how bad I was feeling. This 26-year-old body couldn't hold up anymore," she said. "I don't think it's sunk in and I'm not sure it will."
Hanson's other victories were in the 50 breaststroke, 100 and 200 individual medleys, 100 breaststroke, and she was part of Australia's world record 400 medley relay team.
American Jenny Thompson earned bronze in the 100 butterfly, then came back 25 minutes later to finish seventh in the 50 freestyle in the final race of her career. She lingered in Lane 8 as the other swimmers made their way past her offering congratulations.
"It would have been too cliche to end with a gold medal," she said. "This is a great time for me to stop."
Thompson won the 50 butterfly, swam on the winning 400 freestyle relay team and was part of the second-place 400 medley relay team at the meet. The 31-year-old owns 83 medals from international competition, making her the most decorated swimmer. She is due back at Columbia University's medical school on Tuesday.
The total attendance of 71,659 was the largest in the 10-year history of the short course championships.
"To come here and swim in this atmosphere brings out the best in all of us," Peirsol said.