Bolt bids to defend Olympic 100-meter crown

A day after British athletes stole the show at the Olympic Stadium, Usain Bolt will try to do the same in the London Games' blue ribbon event.

Bolt defends the 100-meter sprint crown he won as part of his three-gold medal haul four years ago in Beijing.

Bolt, who swept the 100, 200 and 4x100 in Beijing, each in world-record time, faces tough competition from his training partner, world champion Yohan Blake, who beat Bolt in the 100 and 200 at the Jamaican Olympic trials.

Bolt did enough Saturday to progress to Sunday night's semifinals, but he was not dominant.

"I stumbled on the start," the 25-year-old Jamaican said. "I really didn't do a lot of executing."

If Bolt executes as expected in the semis, the final is later in the evening.

The games other must-see final has a familiar ring to it: Roger Federer vs. Andy Murray at the All England Club.

The Swiss star beat Murray last month to win his seventh Wimbledon title and is now aiming to add his first Olympic singles title to his bulging trophy cabinet.

Murray will be hoping that the Super Saturday that saw Britain win six golds, including three in an hour at the athletics stadium, will extend into Sunday. The Scot has two chances at gold — he plays in the mixed doubles final with Laura Robson against Victoria Azarenka and Max Mirnyi of Belarus straight after his match with Federer.

A thrilling sailing regatta in the Finn class reaches its climax with a race expected to turn into a showdown between unheralded Dane Jonas Hoegh-Christensen and Britain's most successful Olympic sailor, Ben Ainsley, in the English Channel off Weymouth.

Ainslie is aiming for his fourth straight Olympic gold medal and fifth games medal overall on Sunday. If he gets the gold, he'll eclipse Denmark's Paul Elvstrom, who won four straight golds from 1948-60, as the most successful Olympic sailor ever.

Hoegh-Christensen has led the Finn class since Race 1 and says he feels no pressure despite what's at stake.

"I think I have a very good chance of winning. But you've got to remember, Ben is the best sailor of modern times. He's going to be a hard guy to beat, no doubt about it," Hoegh-Christensen said.

The women's marathon will be held around the streets of London, starting and finishing in the shadow of Buckingham Palace on The Mall.

Britain will be aiming to continue its dominance at the London Velodrome, where the hosts have won four of the five gold medals awarded in track cycling.

Sunday sees the men's omnium reach its conclusion. Bryan Coquard of France will try to maintain his small lead in the newly introduced event which mixes endurance and sprint.

Fresh from the gold medal he won with his British teammates in the pursuit, Ed Clancy got off to a strong start in the event, winning the flying lap with a time of 12.556 seconds. Clancy then moved down to fourth overall with 17 points after the points and the elimination races but is still in contention for the gold medal.

The three remaining races are the individual pursuit, the scratch race and the time trial.

Elsewhere Sunday, medals will be won in the men's floor and pommel horse and in the women's vault at gymnastics and in the women's three-meter springboard in diving.

In all, 23 gold medals are up for grabs Sunday.