09/03/2012 at 10:00 AM EDT
After a storied career in which he won 18 Olympic gold medals,
and 22 medals overall, Michael Phelps celebrated his retirement from competitive swimming this weekend at – what else? – a pool party.
Phelps, 27, who became a legend in Athens, Beijing
, chose Las Vegas as the city for his send-off, enjoying a raucous Saturday afternoon at the Encore Beach Club with friends, fans and fellow swimmers – including his training partner and close friend Allison Schmitt.
The Maryland native was grinning ear to ear as the club's bikini-clad servers gave him a special cake paying tribute to his 22 medals, the most won by any Olympian in history.
Phelps was also joined by fellow U.S. gold medalists Nathan Adrian and Charles Houchin, as well as several other friends, at the luxury bungalow overlooking a sea of pool partiers, with DJ David Guetta spinning tunes.
At one point, Phelps and Schmitt worked their way down past the pool, as fans patted them on the back and a chant of "USA! USA!" broke out.
Phelps's party weekend began Friday night at Vegas's Surrender Nightclub, where he was given a hero's welcome by the packed house.
Along with Schmitt and poker star Phil Hellmuth, Phelps joined his friend Afrojack in the deejay booth and even fired the nitro cannon into the crowd. "This is my first night of retirement at Surrender!" he shouted into the microphone, to deafening cheers.
While his weekend was said to be an overall success – no Prince Harry
here – Phelps did not, as rumor had it, win $100,000 at the poker table. "I wish I won a 100k.... Haha not true tho," he later wrote on Twitter