A hundred here and a hundred there, that's what it will be all about today at the Olympics. The first 100-metre race will come at the Water Cube, where Michael Phelps will be trying to equal Mark Spitz's record of winning seven gold medals at a single Olympics in the butterfly.
"For me to be a player in that race, I have to be closer at the 50," said Phelps. "I was over a body length behind at the 50 in the prelims and came up a bit short, so I have to be there."
About 12 hours later at the Bird's Nest, it will be the men's 100 sprint, with world record-holder Usain Bolt expected to face Asafa Powell and Tyson Gay in the final.
Those two finals highlight a day when a total of 30 gold medals will be given out as the Beijing Games enters week number two.
Besides the four in the pool and the four on the track, there will be medal events in badminton, rowing, sailing, shooting, tennis, wrestling, cycling, weightlifting and fencing.
Phelps has won all six of his events so far to become the most decorated Olympian ever with 12 overall. He has also set a world record in each of the six events he has won in Beijing.
If Phelps wins, he'll still have to win the 4x100 medley relay with his American teammates to do one better than Spitz, who claimed his seven golds at the 1972 Munich Games.
The other finals at the Water Cube come in the women's 200 backstroke and 800 freestyle, and in the men's 50 freestyle – also known as the "splash and dash."
Bolt and Powell head into the 100 with the two fastest times, Bolt having beat Powell's world record in May with a 9.72 second run in New York.
Gay is also a threat. The world champion, however, hadn't run competitively since injuring his hamstring at the US trials until taking part in the heats a day ahead of the final.
"It feels good," said Gay. "My body is woke up."
The heptathlon will also be decided today, with Kelly Sotherton of Britain the favorite since Carolina Kluft decided to skip the event at the Beijing Games.
The women's shot put and men's 20-kilometre walk are also to be decided.