American swimmer Dana Vollmer won a gold medal and set a world record in the same race on Sunday. Vollmer won the 100 meter butterfly with a time of 55.98 seconds, besting the mark of 56.06 set by Sweden's Sarah Sjostrom in 2009.

This is a great comeback for Vollmer, who failed to qualify for the 2008 games. She was third in the race at the turn, but put on her afterburners in the final 50 meters. She's making American swimmers proud, way to go!

Stay tuned to Weplay's London 2012 Olympics for all of the latest action.

Here's Vollmer Competing In the 100m Butterfly: