LONDON, Aug. 2 (Xinhua) -- U.S. swimming prodigy Michael Phelps, the most prolific medalist the Olympics have ever witnessed, confirmed he would retire after London Olympics.

"No more competitive swimming, no more club meets. I will definitely retire from swimming competitions after London Olympics," said Phelps, owner of the biggest haul of 20 medals in Olympic history.

Phelps has retained a third straight Olympic gold in the 200m individual medley on Thursday, making himself the first male swimmer to win the same Olympic event at three successive Games.

"It is a relief to win an individual gold," the 29-year-old said after the race, adding he was so proud to be the first-ever to defend a third straight Olympic title.

"It's special for me, indeed," he said.

After failing to defend his 200m butterfly and 400m individual medley at London Olympics, Phelps had an epic triumph over compatriot Ryan Lochte in the 200m individual medley final.

Phelps led all the way to power home first in 1:54.27, half-body-length clear over Lochte to prove he is still the man to beat. Lochte bagged a silver to add to his five Olympic medals tally in London.

Describing Lochte as his greatest racer over the years, Phelps said they pushed each other over the years and Lochte had brought the best out of him many times.

Also on Thursday, Phelps breezed into men's 100m butterfly as the fastest qualifier. He said he would go all out for the gold from his farewell show on Friday. Enditem