Liu Zige led a thrilling Chinese one-two in the women's 200m butterfly on Thursday, giving the host country its first swimming gold of the Beijing Games.
With no golds on the horizon for US superstar Michael Phelps - who swam only the semi-finals of the men's 200m medley on Thursday morning - the spotlight fell squarely on the Chinese.
Liu smashed the 200m fly world record, out-dueling previous world record-holder Jessicah Schipper of Australia to seize the gold in 2min 04.18sec.
Jiao Liuyang, lying third at the final turn behind Zige and Schipper, claimed the silver in 2:04.72, also under Schipper's previous world mark of 2:05.40, while the Australian settled for bronze in 2:06.26.
"I didn't expect that I could swim so fast," Liu said. "I have never imagined that I could win the gold in the Olympic Games."
Schipper was under world record pace at the halfway stage, but couldn't maintain her challenge.
The Chinese swimmers sped to the final wall buoyed by the roars of the Water Cube crowd.
"The last 50 metres was hard work, it hurt quite a bit and the Chinese girls swam an awesome race," Schipper said. "I am very happy for them both."
Liu and Jiao emerged from the pool to an ecstatic ovation.
Their medals took China's tally at the pool to four, along with Zhang Lin's silver in the men's 400m freestyle and Pang Jiaying's bronze in the women's 200m freestyle.
"I didn't feel pressure before the competition, I tried to relax," Liu said. "In the race, I just swam at my own pace, not caring about the others."
Jiao said having her teammate in the final made things easier.
"The pressure was much less," she said. "We swam together and I felt like we were in training."
France's Alain Bernard won the men's 100m freestyle gold, overtaking Eamon Sullivan on the closing length to triumph over the Australian who had seized his world record in the event.
Bernard didn't add to the flurry of world records in swimming's blue riband event, but he gave France its first swimming gold of these Games and just their third swimming gold ever.
He also helped make up for French disappointment in the 4x100m freestyle relay, in which they narrowly lost out to Michael Phelps's world record-setting US squad.
Bernard won in 47.21sec, with Sullivan second in 47.32.
Cesar Cielo of Brazil and US relay hero Jason Lezak shared bronze, in a dead heat of 47.67.
Dutch star Pieter van den Hoogenband, vying to become the first man to win the same Olympic swimming event at three games in a row, was fifth in 47.75.
The world record in the event had fallen three times in Beijing.
Sullivan seized the mark from Bernard with a lead-off leg of 47.24sec in the 4x100m freestyle relay on Monday.
Bernard regained the mark with a time of 47.20 in the first semi-final on Wednesday, and Sullivan snatched it back with his astonishing 47.05 in the second semi.
But for Bernard, gold was all that mattered.
"The best moment is when I turned back, and I saw the number one next to my name," he said. "It's huge, unbelievable. At any moment I felt that I could be beaten."
Japanese breaststroke king Kosuke Kitajima was also more than happy to capture his second gold of the Games, and his fourth overall, in the 200m breaststroke despite missing out on a world record.
Kitajima, winner of the 100m breaststroke on Monday in world-record time, repeated the double breaststroke gold he claimed in Athens four years ago.
Kitajima won in an Olympic record 2:07.64, just outside the world record of 2:07.51 he set in Tokyo in June.
He held off a late challenge from Australian Brenton Rickard, who was second in 2:08.88, with France's Hugues Duboscq taking the bronze in 2:08.94.
"I'm very relieved that I got the gold medal," Kitajima said.
The 25-year-old, still the only swimmer to break 2:08 in the event, wasn't too disappointed to miss out on a new record.
"I was going OK until the last 50 metres, and then I ran low on energy, but it was a good swim and I am pleased with the time," he said.
Australia's world record-setting victory in the women's 4x200m freestyle relay gave Stephanie Rice her third gold medal of the Games, after record-breaking wins in the 200m and 400m individual medleys.
Australia won in 7:44.31, with China taking silver in 7:45.93 as the United States settled for bronze in 7:46.33.
