Michael Phelps goes for a 20th Olympic medal on Thursday but faces a dogfight with US team-mate Ryan Lochte in the pool, while the host nation is hoping to pile up the golds when the track cycling starts.
Phelps and Lochte will swim beside each other in the 200m individual medley as the man who has already become the most decorated Olympian in history seeks to avenge a humiliating defeat at Lochte's hands earlier in the Games.
After Britain finally won its first two golds of the Games on Tuesday, its highly successful track cycling squad hit the futuristic Velodrome where a packed 6,000 crowd will roar them on.
The men's and women's team sprint finals will be contested on the opening day of the six-day competition and Britain are among the favourites.
At the Aquatics Centre, Lochte will start favourite to win his second individual gold medal of the Games but Phelps wants to win at least one individual title in London.
The 27-year-old finished second to Lochte when they met in the semi-finals on Wednesday, and Lochte has the mental advantage of his crushing defeat of Phelps in Sunday's 400m individual medley.
But the pressure is off Phelps since he overtook the 18-medal haul of Soviet gymnast Larisa Latynina with two medals on Tuesday night, including the relay gold which clinched the Olympic milestone.
On the eve of the start of action in the athletics, Jamaican sprint pretender Yohan Blake is fielding the inevitable questions about his rivarly with training partner Usain Bolt.
Blake has had the edge over double Olympic champion Bolt this year, beating him in the 100m and 200m in the Jamaican trials, but he insists he will focus on his race and not his illustrious friend.
"I've got no message for Usain Bolt. He's a good guy. I'm not focusing on Usain," Blake said on Wednesday.
"It's all about going out there, focusing and executing the race."
In the gymnastics arena, Gabby Douglas of the United States looks a contender for the women's all-around title after Japan's Kohei Uchimura won the men's gold on Wednesday to confirm his status as the world's outstanding male gymnast.
The badminton tournament limps on after eight women's players were disqualified on Wednesday for 'throwing' matches.
Four pairs in the women's doubles competition -- one from China, one from Indonesia and two from South Korea -- were kicked out as the sport's governing body showed its teeth.
The Badminton World Federation confirmed that the eight -- including Yu Yang and her new partner Wang Xiaoli -- had been disqualified for trying to lose matches in the round robin phase to manipulate the knockout draw.
A last-ditch appeals process was also scrapped in the minutes leading up to the scheduled quarter-final start time.
"The appeals committee chairman rejected the cases... the decision of the disciplinary commission stands," said BWF secretary-general Thomas Lund.
Meanwhile, the Dream Team will expect to book their place in the next round of the basketball tournament when they face Nigeria.