LONDON — Manteo Mitchell kept going after he felt something pop in his left leg halfway through the opening lap in the 4x400-meter relay preliminaries.

Turns out this was one impressive run.

Mitchell finished in 46.1 seconds and helped the Americans tie for first with the Bahamas in 2 minutes, 58.87 seconds Thursday. A few hours later, doctors told him he had a broken leg.

The relay final is set for Friday. The Americans have won the last eight long relays they’ve entered at the Olympics.

“I figured it’s what almost any person would’ve done in that situation,” Mitchell told The Associated Press.

Double-amputee Oscar Pistorius and his South African teammates also reached the 4x400-meter relay final.

The man known as “Blade Runner” because of his carbon-fiber prosthetics will get a chance to run for an Olympic medal after officials accepted South Africa’s protest over a collision and awarded an extra spot in the final. Pistorius already is the first amputee to compete on a Summer Games track.

Caster Semenya, Pistorius’ countrywoman, won her 800-meter semifinal in 1:57.67 to move one step closer to an Olympic medal three years after being forced to undergo gender tests.

Those preliminaries came hours before the main event at Olympic Stadium: the 200-meter showdown featuring Jamaican’s speedy duo of Usain Bolt and Johan Blake.

In the boxing ring, Claressa Shields danced, brawled and even stuck out her tongue. The exuberant American teenager also managed to win the first middleweight gold medal in the new Olympic sport.

Irish lightweight Katie Taylor and British flyweight Nicola Adams also won gold at the landmark tournament, claiming the first Olympic titles in a growing women’s sport that was banned in Britain until 1996.

The five-day event was one of London’s biggest hits. And even amid the sea of Irish fans cheering Taylor’s every move, the 17-year-old Shields was one of the breakout stars of the games.

Shields’ power and elusiveness were far too much for 33-year-old Russian Nadezda Torlopova, nearly twice Shields’ age and half her speed at times. Shields won fairly easily, 19-12.

The U.S. women’s basketball team faced its first challenge of the Olympics, and found a way to advance to the final.

Trailing early in the second half, coach Geno Auriemma turned to his Olympic rookies and the group — led by Tina Charles and Lindsay Whalen — pressured Australia into turnovers and bad shots. That led to a pivotal scoring run in the third quarter of an 86-73 victory.

The Americans, seeking a fifth straight gold medal, will meet the winner of the France-Russia semifinal.

Lauren Jackson finished with 14 points for Australia.

The IOC is set to formally strip American cyclist Tyler Hamilton of his gold from the 2004 Athens Games and reassign the medals after his admission of doping, according to an Olympic official familiar with the case.

With the eight-year deadline approaching, the official told the AP that the IOC executive board will meet Friday to readjust the standings from the road race time trial and award the gold to retired Russian rider Viatcheslav Ekimov.

The official spoke on condition of anonymity because the decision hasn’t been announced yet.

After years of denials, Hamilton told CBS’ “60 Minutes” last year that he had repeatedly used performance-enhancing drugs. The IOC asked for documents from the U.S. Anti-Doping Agency before reallocating the medals.

The gold will now go to Ekimov, a former teammate of Hamilton and Lance Armstrong.

American Bobby Julich will be moved up from bronze to silver, and Michael Rogers of Australia from fourth to bronze.