Michael Phelps swims in a men's 200-meter butterfly semifinal Monday. Phelps won the semi-final race and will compete in the final Chuck Myers / MCT

USA's Michael Phelps leaps from the starting block in the men's 200-meter butterfly semifinal Monday. Robert Gauthier / Los Angeles Times/MCT

U.S. swimmer Michael Phelps leaves his block at the start of a men's 200-meter butterfly semifinal Monday. Chuck Myers / MCT

USA's Missy Franklin competes in the women's 100-meter backstroke final Monday. Robert Gauthier / Los Angeles Times/MCT

USA's Missy Franklin smiles after winning the women's 100-meter backstroke final Monday. Robert Gauthier / Los Angeles Times/MCT

U.S. swimmer Missy Franklin stands on the podium Monday after receiving her gold medal for the women's 100-meter backstroke. Robert Gauthier / Los Angeles Times/MCT

Matthew Grevers of the United States, left, and USA teammate Nick Thoman celebrate after they finished first and second in the men's 100-meter backstroke final Monday. Robert Gauthier / Los Angeles Times/MCT

Matthew Grevers of the United States, left, and USA teammate Nick Thoman celebrate after they finished first and second in the men's 100-meter backstroke final Monday. Robert Gauthier / Los Angeles Times/MCT

Matthew Grevers of the United States, left, and USA teammate Nick Thoman celebrate after they finished first and second in the men's 100-meter backstroke final Monday. Robert Gauthier / Los Angeles Times/MCT

Ruta Meilutyte of Lithuania, left, and Rebecca Soni of the United States battle it out in the women's 100-meter breaststroke Monday. Meilutyte won the gold, finishing ahead of Soni by 0.08 seconds. Chuck Myers / MCT

Ruta Meilutyte of Lithuania, right, is congratulated by Rebecca Soni of the United States, after winning the women's 100-meter breaststroke Monday. Chuck Myers / MCT

Ruta Meilutyte of Lithuania waves to the crowd after winning the gold medal in the women's 100-meter breaststroke Monday. Chuck Myers / MCT

U.S. swimmer Michael Phelps checks out the scoreboard following a men's 200-meter butterfly semifinal Monday. Chuck Myers / MCT

U.S. swimmer Michael Phelps stretches before the start of a men's 200-meter butterfly semifinal Monday. Chuck Myers / MCT

USA's Matt Grevers listens to the U.S. national anthem Monday after accepting a gold medal for winning the men's 100-meter backstroke. Robert Gauthier / Los Angeles Times/MCT