Aaron Peirsol (USA) retained his 100m backstroke crown in a world record of 52.54 off a split of 25.65. Giant of a teammate Matt Grevers was just 0.03sec back at the turn but could not withstand the assault launched by the champion on the way home: 26.89 to 27.43. Grevers held on for silver in 53.11, with Arklady Vyatchanin (RUS) taking a shared bronze in 53.18 with Hayden Stoeckel (AUS).

• The splits: 25.65; 52.54
  
• Former splits (Omaha July 1, 2008: 25.60; 52.89.