Smashing a nearly half-century-old Olympics record held by Soviet gymnast Larisa Latynina, American swimmer Michael Phelps on Tuesday became the most decorated Olympian, winning his 15th gold medal in the 4x200m swimming freestyle relay at the London games.

The 27-year-old swimmer has won a record 19 medals — 15 golds, two silvers and two bronzes — in an Olympics career spanning 12 years.

The legendary swimmer won six gold medals at the Athens Olympics in 2004 — where he also won two bronze medals — and topped it with a spectacular performance at the Beijing Olympics in 2008, winning eight golds. In London, he has managed to win just two silvers, before Tuesday’s gold in the relay. Phelps missed shattering another record when he came second, losing by a mere 0.05 seconds to South Africa’s Chad le Clos in the 200m butterfly, his signature event. Had he won the gold, he would have been the first person to win the same Olympic swimming event in three successive Games.

But despite that setback, the American did not allow it to dampen his enthusiasm, returning an hour later to win the 4x200m free relay gold along with compatriots Ryan Lochte, Conor Dwyer and Ricky Berens.

No other swimmer, athlete or sportsman or woman has ever won so many medals in either the summer or winter Olympics. Soviet gymnast Latynina won 18 medals (including nine golds, five silvers and four bronzes) between 1956 and 1964. Only three other individuals have won nine golds in the Olympics: Finnish athlete Paavo Nurmi (1920-28), with a total medals tally of 12; American swimmer Mark Spitz (1968-72) and US athlete Carl Lewis (1984-96).

With age — and younger swimmers including the South African — catching up fast, Phelps has just three more medals opportunities at the London Games, perhaps his last Olympics: in the 100m butterfly, the 200m individual medley and the 4x100 medley relay. But his record haul of 15 golds and 19 medals in the Olympics is unlikely to be overtaken soon.

The closest that any contemporary sportsperson has come to this medal tally is Norwegian professional biathlete, Ole Einar Bjorndalen, who has won six winter Olympics gold medals, four silvers and a bronze. But at 38, he is unlikely to overtake Phelps’ tally.

Le Clos, the 20-year-old South African who deprived Phelps of the gold in the 200m fly on Tuesday, says the American swimmer has been his childhood hero. “The legacy that he’s left behind for swimming is fantastic,” said Le Clos. “He has changed the way people around the world view swimming. He is definitely the greatest Olympian of all time.”