London Catch-Up, Day 8: A fitting finale for Michael Phelps

1. In the final swim of his unparalleled career, Michael Phelps put his record Olympic medal tally a little further out of reach. Phelps' butterfly leg propelled the U.S. to a dominant victory in the 400-meter individual medley, sending him into retirement with 22 medals and 18 golds. He leaves London with four golds and two silvers, not a bad haul considering he missed the podium in his first race.

2. Jamaica's Shelly-Ann Fraser-Pryce became the first woman to defend her 100 meters Olympic championship since Gail Devers did it in 1996. Fraser-Pryce edged world champ Carmelita Jeter of the United States, winning the race in a blistering 10.75 seconds. Six women ran under 11 seconds.

3. It was unrealistic to expect Team USA to outclass every opponent the way it did Nigeria on Thursday, but Saturday's 99-94 win over Lithuania was a bit too close for comfort. Lithuania, whose best player is NBA journeyman Linas Kleiza, actually led 84-82 with 5:50 to play on a bucket by Kleiza. Only a series of quick scores from LeBron James in the clutch prevented Lithuania from springing the upset.

4. How dominant was Serena Williams' 6-0, 6-1 annihilation of Maria Sharapova in Saturday's women's tennis gold-medal match? When Sharapova won her lone game, the crowd at Wimbledon let out a large cheer and she pumped her fist in celebration. Williams' 63-minute demolition of Sharapova was a fitting finish to her march to her first Olympic singles gold medal. Not only did Williams not lose a set in six matches, she dropped just 17 games.

5. An ill-timed hamstring injury will prevent reigning Olympic 400 meters champion LaShawn Merritt from defending his title. Merritt developed a hitch in his stride midway through his qualifying heat Saturday, faded on the back stretch and pulled up with a look of anguish on his face. His absence makes Grenada's Kirani James the clear-cut favorite to win gold in the 400 meters. It also gives other contenders more hope of challenging the U.S. in the 4x400-meter relay, a race the Americans have traditionally dominated.

A dead heat in a sprint? Maybe a bit unusual. A dead heat in the women's triathlon? Simply stunning. Switzerland's Nicola Spirig and Sweden's Lisa Norden swam 1,500 meters, biked 26.7 miles and ran 10km on Saturday, yet 5.9 inches was all that separated them at the finish line. Judges awarded Spirig the gold and Norden the silver. (AP)

"Shaq on the free throw line today!!! My bad USA." — Kevin Love on his 3-for-8 shooting from the foul line against Lithuania on Saturday. Team USA won 99-94, but Love's uncharacteristically poor free-throw shooting contributed to the game being far closer than expected. (Twitter)

Saturday's Gold Medal Moments for Team USA: Serena Williams, women's tennis singles; Bob and Mike Bryan, men's tennis doubles; Jamie Lynn Gray, women's 50-meter three-position rifle shooting; men's 400 medley relay; woman's 400 medley relay

U.S. Olympians with best chance at gold on Sunday: Sanya Richards-Ross, women's 400 meters; Serena and Venus Williams, women's tennis doubles