U.S. phenom Michael Phelps tied Mark Spitz's record of seven gold medals in a single Olympics, taking the men's 100-meter butterfly by one hundredth of a second for his seventh swim title Saturday in Beijing.

Halfway through the Aug. 8-24 Games, China maintained a runaway lead on the gold medals table with 27 after seven of Saturday's 29 medal events, but the Americans had 48 overall medals, ahead of China's 43.

American Michael Phelps won the men's 100m butterfly gold medal at the Beijing Olympic Games on Saturday.(Xinhua/Wang Dingchang)

Phelps was trailing in seventh place halfway through and overtook Serbia's Milorad Cavic with his last stroke to win by 0.01 second in 50.58 seconds -- an Olympic record. Australia's Andrew Lautersetein got the bronze in 51.12.

Following the race, the Serbian team protested the results, suggesting that the Serbian swimmer touched the wall first, but was later rejected.

"Beforehand, Bob (his coach) said it would be good for me if I lost. When he said that I was fired up. I said, 'I'm going to go for it'," Phelps told reporters.

"When I saw the replay, when I did take that extra half stroke I thought that had lost the race.

"But I guess when I took that half stroke that was what I needed. I'm at a loss for words," he added.

The 23-year-old Phelps could break Spitz's record set at the 1972 Olympics if the U.S. wins tomorrow's 400-medley relay, an event the U.S. has won at every Olympics in which it competed since the relay was added in 1960.

Zimbabwe's Kirsty Coventry, who has already won three silvers in her first tries at the Games, finally improved on that for a gold in the women's 200m backstroke. Coventry touched home in 2:05.24, beating the previous mark of 2:06.09 set by Margaret Hoelzer.

Rebecca Adlington, who had won Britain's first Olympic title in women's swimming since 1960 in the 400m freestyle on Monday, smashed a 19-year-old world record to strike gold in the 800m freestyle. Adlington clocked 8:14.10, chopping 2.12 seconds off the previous best which stood since 1989, the year she was born.

Cesar Cielo Filho captured Brazil's first ever Olympic swimming gold by taking the blue-ribbon event - men's 50m freestyle in 21.30, an Olympic record time.

Cielo couldn't help crying after the race and shed tears again when the Brazilian national anthem was played during the awarding ceremony.

"I'm extremely happy. I was a little nervous before the race but I think that was my best race ever," said the 21-year-old.

China's Zhang Ning successfully retained her Olympic crown after beating fellow countrywoman Xie Xingfang in a three-set thriller in the women's singles badminton final.

Ukraine's Oleksandr Petriv dethroned Germany's three-time Olympic champion Ralf Schumann to win gold in the men's 25m rapid fire pistol event. The 34-year-old Petriv, who is making his Olympic debut, finished with a Games record of 780.2 points, just 0.7 points ahead of Schumann.

With 13 of the 15 shooting events contested, China has four golds, followed by the Czech Republic and Ukraine with two each.

Russia's Valeriy Borchin, who served a one-year ban over doping offense between 2005 to 2006, claimed the men's 20km walk title in 1 hour 19 minutes 01 second.

The eye-catching men's 100m dash is scheduled Saturday night, with the three fastest runners of all-time - Usain Bolt, Asafa Powell and Tyson Gay vying for the coveted honor.

Editor: Yan