2012 Olympics: Best of Day 8 (28 images)

Michael Phelps of the United States holds a trophy for the most decorated olympian presented to him after he won his 18th Gold Medal in the Men's 4 X 100M Medley Relay Final at the London 2012 Summer Olympics on August 4, 2012 in Stratford, London. Phelps has won 22 total Olympic Medals. UPI/Brian Kersey

USA's Michael Phelps swims the Butterfly leg of the Men's 4x100 Medley Relay Final at the Aquatics Center during the London 2012 Summer Olympics in Stratford, London on August 4, 2012. The USA team won and Phelps won his record 18th gold and 22nd Olympic Medals to end his Olympic career. UPI/Pat Benic

USA's Matt Grevers starts the Backstroke to help the USA team win the gold in the Men's 4x100 Medley Relay Final at the Aquatics Center during the London 2012 Summer Olympics in Stratford, London on August 4, 2012. Michael Phelps won his record 18th gold and 22nd Olympic Medals to end his Olympic career. UPI/Pat Benic

Matthew Grevers (L-R), Michael Phelps, Nathan Adrian and Brendan Hansen of the United States pose for photographers after their Gold Medal in the Men's 4 X 100M Medley Relay Final at the London 2012 Summer Olympics on August 4, 2012 in Stratford, London. The United States won the Gold with a time of 2:29.35 in the final. UPI/Brian Kersey