phelpsfly

Michael Phelps again bested his nemesis in 100 butterfly qualifying. (Christophe Simon -- AFP/Getty Images)

Michael Phelps again bested his nemesis in 100 butterfly qualifying. (Christophe Simon — AFP/Getty Images)

US swimmer Michael Phelps leaves the pool after competing in the men’s 100m butterfly heats swimming event at the London 2012 Olympic Games on August 2, 2012 in London. AFP PHOTO / CHRISTOPHE SIMONCHRISTOPHE SIMON/AFP/GettyImages