China still heads the medal table, more records in the pool, first doping disqualification.
Michael Phelps' dream of a record eight gold medals was dramatically kept alive by teammate Jason Lezak in a 4x100m freestyle relay thriller Monday, while the first drugs scandal of the Beijing Olympics emerged.The win gave Phelps two golds from two events, but the kudos went to US relay anchor Lezak who dived into the pool more than a body length behind France's Alain Bernard and made up the deficit with his final strokes.
At 50m to go Lezak told himself there was "no way" he could catch Bernard and save Phelps' quest.
"Then I thought: 'That's ridiculous, this is an Olympic Games. You have to go for it'," he said.
The US took an astonishing four seconds off the world record they had set in the heats the previous day, posting a new mark of 3min 08.24 sec.
"Unbelievable!" said Phelps. "Jason finished that race way better than we could have even asked for.
"The last 10 to 15 metres were incredible. I lost my voice, and I was definitely pretty emotional after that.
"Such was the pace of the race, Australia's Eamon Sullivan added to Bernard's heartache when he broke the Frenchman's 100m freestyle world record as he headed Phelps in the lead-off leg.
Despite the win, the United States remained third in the medals table at the end of the third day and 34 events with three gold medals behind hosts China with nine and South Korea with four.
China won three gold on Monday, including Lin Yue and Huo Liang in the men's synchronised 10m platform dive where British 14-year-old Tom Daley was a distant eighth and last with teammate Blake Aldridge.
Zhang Xiangxiang and Chen Yanqing also claimed gold in weightlifting.
Phelps, who began his unprecedented eight-gold quest on Sunday with a world record win in the 400m individual medley, raced three times Monday, qualifying fourth fastest in the 200m freestyle an hour before the relay in the morning.
The 23-year-old then returned in the evening to break the Olympic record in his 200m butterfly heat.
Beijing's unique swimming venue continued to churn out world records with five more on Monday.
In addition to the two in the men's relay, Japan's gold medal winning Kosuke Kitajima regained the 100m breaststroke world record he lost four years and Kirsty Coventry of Zimbabwe broke the 100m backstroke world record in her semi-final ahead of Tuesday's final.
Federica Pellegrini of Italy shaved 0.07sec off the women's 200m freestyle world record in her evening heat with the final on Wednesday.
Rebecca Adlington ended British women's 48-year wait for a swimming gold when the 19-year-old was a surprise winner of the 400m freestyle.
Spanish cyclist Maria Isobel Moreno became the first athlete to fail a doping test at the Games, after returning a positive EPO sample.
Meanwhile, weightlifter Monika Devi, who was dropped from the India team on doping charges last Tuesday, has now been cleared but officials said it was too late to get her back into the Games.
But India had reason to celebrate when Abhinav Bindra secured their first ever individual Olympic gold medal winning the men's 10m Air Rifle shooting.
The women's tennis singles suffered another withdrawal when India's Sania Mirza retired with a wrist injury, while in the men's singles fifth seed David Ferrer of Spain and Britain's sixth seed Andy Murray both crashed out in the first round.
Women's third seed Svetlana Kuznetsova also made an early exit, beaten in straight sets by China's Li Na, while the men's top seeds Roger Federer, Rafael Nadal and Novak Djokovic safely negotiated their way to the second round.
Serena and Venus Williams both won comfortably to move into the second round and stayed on course for an all-Williams final.
Italy's Valentina Vezzali made Olympics history when she became the first fencer to win three successive individual titles with victory in the foil.
The 34-year-old, the champion in 2000 and 2004, defeated South Korea's Nam Hyun-Hee 6-5 in the final.