Michael Phelps won a record 19th Olympic medal as he helped the US team to gold in the 4x200m freestyle relay.
It means Phelps also picked up his 15th gold medal as he swam the anchor leg to complete a winning time of six minutes 59.70 seconds ahead of France in second and China in third.
Ryan Lochte put the US team in total control with a blistering first leg and they barely lost their advantage.
Most successful Olympians
Michael Phelps: swimming, 2000-12, 19 medals
Larisa Latynina: gymnastics, 1956-64, 18 medals
Paavo Nurmi: athletics, 1920-28, 12 medals
Mark Spitz: swimming, 1968-72, 11 medals
Carl Lewis: athletics, 1984-96, 10 medals
Phelps overtakes Russian gymnast Larisa Latynina who won 18 medals.
Phelps still has three more races at London 2012 before he retires and could establish a record that would be difficult for anyone to beat.
“It has been a pretty amazing career,” he said, “but we still have a couple races to go.”
Just minutes before the relay victory, the 15-time gold medallist had claimed his 18th Olympic medal with a silver behind South Africa’s Chad le Clos in the 200m butterfly.
Le Clos came from behind to touch the wall in one minute 52.96 seconds, just 0.05secs ahead of Phelps.
“Chad swam a great race and I’ve gotten to know him over the past year and he’s a hard worker, tough competitor and a racer and you know it was obviously my last one I would have liked to have won, but you know one minute 53 seconds isn’t a terrible time, if you look at the picture of it it’s a decent time.
The 15th gold did not take long to come, however, the American team had a lead of four seconds going into the last leg of the 4x200m freestyle relay – mainly thanks to Lochte’s fast start.
At the end of the race, Phelps, Lochte, and the other two members Conor Dwyer and Ricky Berens huddled together in an emotional moment.
“I thanked those guys for helping me get to this moment,” Phelps said.
“I told those guys I wanted a big lead. I was like, ‘You better give me a big lead going into the last lap,’ and they gave it to me. I just wanted to hold on. I thanked them for being able to allow me to have this moment.”
Great Britain’s team of Robbie Renwick, Ieuan Lloyd, Rob Bale and Ross Davenport finished sixth in the race.