Usain Bolt bids to become the first man to win the Olympic sprint double twice while World Cup champ Japan seeks to win a second major soccer title.
Here are five things to watch at the Olympics on Thursday:
1) Men's 200 meters: Jamaica vs. Jamaica
Before you go giving Bolt the gold medal, Yohan Blake has something he wants to say. "I'm not really focusing on beating him. I'm concentrating on running my race. My plan is just to execute," says the Jamaican champion. Wallace Spearmon of the United States will try to spoil the race, but after Blake and Bolt looked so impressive in their heats, it's hard to see anyone challenging the training partners and friends.
Final is at 8:55 p.m. London time (3:55 p.m. ET)
2) Soccer: U.S. looks for revenge in the Olympic final, again
The World Cup "loss" in 2011 was one of the most heartbreaking results ever for the U.S. women. The U.S. led with nine minutes left in regulation and with three minutes left in extra time but lost the penalty-kick shootout to Japan 3-1 (the match result is deemed a draw). The Americans, twice World Cup champs and three times winners of the Olympics, have several factors going for them in their revenge bid. No World Cup champion has ever won the Olympics the next year. And since 1995, each time a team has knocked the United States out of World Cup, they've met in the Olympics a year later. The United States has won every time, twice in the final.
Gold medal match begins at 7:45 p.m. London time (2:45 p.m. ET).
3) Decathlon: Eaton needs a good nap
Ashton Eaton appears ready to grab the title of world's greatest athlete that comes with winning the Olympic decathlon title. After the first day of the competition, the world record holder in the event had a nice 220-point lead over his countryman Trey Hardee. You'd think Eaton would be thrilled after breaking the Olympic record for the decathlon 100 meters and topping the pack in three events. Not so, after all, he's only halfway home. And after a 12-hour day, he was in a hurry to go get some sleep. "So far I am somewhat satisfied. I am in a good position. It has been a long day," he said.
The first of the five events on Day 2, the 110-meter hurdles, is at 9 a.m. London time (4 a.m. ET)
4) Women's water polo: Upstarts vs. U.S.
Perhaps the fourth time will be the charm for the United States. Since women's water polo became an Olympic sport in 2000, the Americans have medaled three times, but none are gold. Teenager Maggie Steffens leads the United States with 16 goals against Spain, which has never won a major tournament. Spain is led by Anni Espar Llaquet, who has 13 goals.
The gold medal match is at 8 p.m. London time (3 p.m. ET). Water polo placement matches begin at 2:30 p.m. London time (9:30 a.m. ET)
5) Women's 4x100-meter relay: Trying to get a handle
Passing the relay baton seems like it should be an easy thing to do. But in the past two Olympics (and several world championships) the U.S. women have botched a pass and not finished a race. The Americans begin their London quest with a qualifying heat Thursday night. Jeneba Tarmoh, who passed on a runoff for a place in the 100 meters after tying Allyson Felix at the U.S. trials, is part of the six-member pool. She might run in the early rounds. But Tarmoh ran with an "A" relay squad in a tuneup meet and the result was familiar: a missed handoff.
Round 1 of the relays begins at 8:20 p.m. London time (3:20 p.m. ET)