Following are four highlights to look out for on the first full competition day of the London Olympics on Saturday.

- The Aquatics Center will ignite shortly after 19:30 on Saturday as American superstar Michael Phelps looks to clinch his first of a potential seven golds in London in the final of the 400m individual medley. His in-form teammate Ryan Lochte is a strong competitor.

- Mark Cavendish of Britain leads what he calls a 'dream team' of cyclists, including Tour de France winner Bradley Wiggins as Britain bids for an early gold medal in the men's road race between 10:00 and 16:00 on Saturday. This is Cavendish's time to shine after helping Wiggins become Britain's first winner of the Tour.

- Yi Siling of China, the world No. 1, is the favorite to win the first gold medal of the London Games when she competes in the women's 10m air rifle event at the Royal Artillery Barracks on Saturday.

- Wimbledon champions Roger Federer of Switzerland and Serena Williams of the United States will be back in action at the scene of their triumphs three weeks ago in first-round men's and women's singles matches. Williams faces Jelena Jankovic of Serbia while Federer takes on Alejandro Falla of Colombia. Home favorite Andy and Jamie Murray are also involved in doubles.