The seventh world record of the competition in the men's 4x200 free relay was the fourth day's highlight.
Tom Malchow (USA) won the 200 fly in the second- fastest time ever, Susie O'Neill (AUS) won the 200 free, and Joanne Malar (CAN) won the 200 IM.
The USA moved ahead in total medals with 17 (5-6-6), with Australia 16 (8-6-2) still ahead on golds.
Lindsay Benko (USA) had the lead for the first three lengths, splitting 27.86 at the 50, 57.58 at the 100, and 1:28.00at the 150. Susan O'Neill (AUS), in second with 28.14 at the 50 and 58.01 at the 100, closed the gap at the 150 with 1:28.03, and moved into the lead on the final length, winning in 1:58.17, a Commonwealth and Australian record and a full second improvement over her previous best.
Benko placed second with 1:59.60 and Ellen Stonebraker (USA) third with 2:00.46
Inspired by all the record setting, Tom Malchow (USA) was on record pace, but fell short at the end. His time of 1:55.41 is the second-fastest 200 butterfly time ever.
Takashi Yamamoto (JPN) was second with 1:57.33 and Ugur Taner (USA) third with 1:57.82.
"It was close," Malchow said. "There is something out there for me to keep shooting for, to keep me focused. Hopefully I will be back here next year-maybe I'll be ready next time to go that fast."
Tomoko Hagiwara (JPN) had the lead for the fly (28.76) and back (1:01.99). Elli Overton (AUS) was second at the 100 with 1:03.17, with Cristina Teuscher (USA) third in 1:03.52 and Joanne Malar (CAN) fourth in 1:03.95. Holding back for the first half was the right strategy as Malar made her move in the second half, moving into the lead on the breaststroke leg and holding off a fast-charging Teuscher.
Malar's winning time of 2:13.63 was a Commonwealth and Canadian record. Teuscher was second with 2:14.31 and Overton third with 2:14.51. Hagiwara, the early leader, missed the podium.
"When I touched the wall I was happy, but I know I can go faster than that," Malar said. "I felt pressure to win because I wanted to end my last individual race on a high note. This has been the best season of my career. I've really learned to swim fast. And being here was so inspirational."
The crowd sensed a world record and got behind the Australian team.
Ian Thorpe just missed the world record in the lead-off leg. Newcomer to the relay team, Bill Kirby, increased the lead over the USA. Grant Hackett swam third and showed no effects from the virus he had contracted early in the week. Michael Klim then anchored in fine style to take an amazing three seconds off Australia's record time from the 1998 Commonwealth Games in Kuala Lumpur.
The crowd went wild, appreciating the piece of history they had witnessed.
Semi-finals were held in the men's 100 free with Michael Klim (AUS) leading all qualifiers with 49.39. Simon Cowley (AUS) was fastest in the men's 200 breaststroke with 2:13.21.
In the women's 200 fly, Susan O'Neill (AUS) swam 2:06.53 and had everyone anticipating the final on the next day where she would attack the oldest remaining world record of 2:05.96 from 1981.