US swimmer Michael Phelps holds his Laureus Academy Exceptional Achievement trophy during the Laureus World Sports Awards in Rio de Janeiro, Brazil, on March 11, 2013. [Photo/icpress.cn]

How impressive is Phelps' legacy? Here's a look at five of his most memorable moments:

GREAT HAUL OF CHINA

Phelps will forever be linked to his remarkable performance in Beijing, where he won eight gold medals (five individual, three relays) to break Mark Spitz's iconic Olympic record. Only 11 other athletes have won as many gold medals in their careers as Phelps won during that magical week in China. For good measure, he set or was part of seven world records. The only time he missed out might have been his most impressive triumph _ rallying to beat Milorad Cavic by one-hundredth of a second in the 100-meter butterfly.

DOUBLING DOWN

Phelps became the first swimmer to set world records in two different events on the same day at the 2003 world championships in Barcelona. He took down the mark in the 100-meter butterfly during a semifinal heat and smashed his own record in the final of the 200 individual medley about an hour later.

LONDON CALLING

After serving a three-month suspension over an embarrassing bong picture and facing doubts about whether he wanted to keep competing, Phelps returned for his fourth Olympics in 2012. He swam seven events _ one less than in 2004 and 2008 _ and started out with a disappointing fourth-place finish in the 400 IM. He bounced back to win four golds and two silvers, smashing Soviet gymnast Larisa Latynina's record of 18 career medals.

YOUNG MICHAEL

In 2000, Phelps qualified for his first Olympic team at age 15, making him the youngest U.S. male swimmer since 1932. The following year, still three months short of his 16th birthday, he became the youngest male to set a world record in the 200 butterfly.

AUSSIE, AUSSIE, AUSSIE

A bit overlooked given Phelps' Olympic dominance was his performance at the 2007 worlds in Melbourne, Australia. Tuning up for Beijing, he went 7-for-7 with five world records. Alas, he didn't get a chance to claim an eighth victory through no fault of his own; the heavily favored US team was disqualified in the prelims of the 400 medley relay while Phelps was resting up for the final.

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