Michael Phelps reached for the highest peak of Olympic achievement with his fingertips on Saturday, winning his seventh gold medal to join fellow-American swimmer Mark Spitz and is now poised to climb the summit alone.
The 23-year-old Phelps equaled Spitz's 1972 record haul of seven golds at a single Games when he won the men's 100 meters butterfly final in 50.58 seconds, touching out Serbia's Milorad Cavic by 0.01 seconds, the smallest margin possible in the Olympic pool.
Serbia lodged a protest over the result, initially believing their man had won, but the sport's world governing body threw out their appeal after watching video replays.
"There was no doubt whatsoever that the first arrival was Michael Phelps," said FINA executive director Cornel Marculescu. "(Serbia) were very satisfied, they agreed with the comments of the referee."
Phelps looked to be in danger of suffering his first defeat in the Water Cube when he was seventh as the field turned for home, before he summoned his strength to pass the others then swim down the Serb on the final stroke.
Cavic had appeared to be heading to touch the wall first when Phelps's massive two-meters wing span inched him past the Serb to pull off the victory that sent the Water Cube into frenzy.
"I was starting to hurt for the last 10 meters, it was my last individual race and I just wanted to finish as strong as I could," Phelps said.
"I actually thought when I did take that half stroke I thought I had lost the race right there, but I guess that was the difference in the end."
It was the first time Phelps had failed to break a world record in a final at Beijing but by equaling Spitz, he earned himself an instant $1 million bonus from his sponsors and the likelihood of plenty more to come in endorsements.
Immediately after Phelps dragged himself out of the pool, Britain's Rebecca Adlington broke the oldest world record in swimming to win the women's 800 freestyle and claim her second gold after winning the 400 last Monday.
The 19-year-old cruised to victory in 8:14.10 to slash 2.12 seconds off the old mark of 8:16.22 set by American Janet Evans in Tokyo in 1989, six months after Adlington was born.
Italian Alessia Filippi finished a distant second in 8:20.23 to collect the silver while Denmark's Lotte Friis was third in 8:23.03 to get the bronze.
"If anyone would have said before the Games that I'd win two golds and break the world record, I'd have laughed in their face, I'd never thought it," Adlington said.
Zimbabwe's Kirsty Coventry also set a world record to successfully defend her 200 backstroke title she won in Athens four years ago, lifting the total of swimming records in Beijing to 23 with one day to go.
Coventry, who had won three silvers already in Beijing, led from start to finish to win her first gold of the Games in 2:05.24, carving 0.85 off the old record set by American Margaret Hoelzer, who finished second to claim the silver medal.
Japan's Reiko Nakamura took the bronze medal.
Cesar Cielo Filho became the first Brazilian to win an Olympic swimming gold medal when he won the men's 50 freestyle sprint in 21.30. France's Amaury Leveaux finished second in 21.45 while his compatriot and 100 gold medalist Alain Bernard was third in 21.49.
"There are two Frenchmen on the podium," Leveaux said. "We won medals in a race that has been dominated for years by madmen. It's crazy."