POSTED: Tuesday, August 7, 2012 - 11:30am
UPDATED: Tuesday, August 7, 2012 - 11:34am
LONDON (CNN) — Athletes are battling for 21 gold medals in 10 different sports Tuesday, with a day of drama promised in the Olympic Stadium -- site of the track and field events -- and in the velodrome and the gymnastics arena.
There was early exaltation for the home crowds, as brothers Alistair and Jonny Brownlee of Team GB split gold and bronze between them in the triathlon, with Spain's Javier Gomez winning silver.
Thousands of flag-waving spectators had flocked to watch the competitors in the men's triathlon swim in the chilly Serpentine lake, cycle laps of the Hyde Park area and run a final grueling 10 kilometers.
Alistair strolled over waving a Union flag as he claimed an emphatic win, while Jonny Brownlee made a brave recovery to take bronze after taking a 15-second time penalty for a bungled transition between phases.
Back in the buzzing Olympic Stadium, four more athletics golds are on the table during the evening session -- including the men's 1,500-meter, where Kenya's defending champion Asbel Kiprop is looking to make it two in a row, and the women's 100-meter hurdles.
Australia's Sally Pearson is the hot favorite for the hurdles, but American Lolo Jones will be hoping to make up for her heartbreak in Beijing, when she lost out on a win after catching the second-to-last hurdle.
Tuesday morning, 100-meter champion Usain Bolt and fellow Jamaican Yohan Blake, nicknamed "the Beast," eased through in their respective 200-meter heats.
Team USA's Maurice Mitchell clinched the third heat, while France's Christophe Lemaitre clocked the fastest time of the morning to win his heat.
Other finals in the stadium Tuesday include the men's discus and high jump, where American world champion Jesse Williams takes on Russia's Olympic champion Andrey Silnov.
There was early disappointment for Team GB, though, as triple jumper Phillips Idowu failed to make it through the qualification round. The athlete, an east London native and Beijing silver medalist, had been the focus of much injury speculation in the run-up to the Games.
In the gymnastics at North Greenwich Arena, Team USA's pint-size gold medalists Gabby Douglas, Aly Raisman and Jordyn Wieber will go for gold again in the individual events.
Douglas is pinning her hopes for another medal on an outstanding beam performance, after disappointment in the uneven bars Monday, when she came eighth.
"It was an amazing finals with so many great competitors," she said after that event. "Coming into bar finals was a big challenge for me, and I made a little mistake. Even if I would have hit a solid routine, I know I have a lower start value than the other competitors."
Among her rivals Tuesday will be Raisman, who lost out on a medal in the women's all-around. Raisman and Wieber also will compete in the women's floor exercise.
In the velodrome, the scene of some of the greatest successes for Team GB, cyclist Chris Hoy is aiming to clinch his sixth medal in the men's keirin.
Meanwhile, Victoria Pendleton, another British cycling hero sure to be cheered on by a noisy home crowd, hopes to win gold in the women's sprint.
In men's football at Wembley, semifinal games will be played between Mexico and Japan, and between South Korea and Brazil -- who despite their soccer World Cup triumphs have yet to win an Olympic gold.
Monday saw drama on the football pitch, as the U.S. women snatched a thrilling 4-3 extra time victory over Canada with a last-gasp headed goal by American Alex Morgan.
The U.S. will meet World Cup winners Japan in Thursday's final at Wembley Stadium, a rematch of last year's Cup final in which Japan won the penalty-kick shootout 3-1.
China topped the medals table as of lunchtime on day 11, with Team USA placed second and Team GB in third, after a series of outstanding performances that have delighted the home crowd.