(L-R) Antonina Krivoshapka of Russia and DeeDee Trotter of the United States compete in the Women's 400m Semi Final on Day 8 of the London 2012 Olympic Games on 4 August 2012 (Getty Images) © Copyright

London 2012 - Event Report - Women's 400m Semi-Final

World leader Antonina Krivoshapka produced the fastest time of the women’s 400m semi-finals to set up a tantalising final on Sunday night.

Chiseling out a hefty lead over the first half in the third of three heats, the 25-year-old Russian forged on to a 49.81 victory, the third sub-50 of the season for the 2009 World bronze medallist. Confident of victory, she slowed over the waning 50 metres, allowing strong finishing DeeDee Trotter of the U.S.A. and Jamaican Novlene Williams-Mills to make up substantial ground and also dip under 50 seconds. Trotter, who was fifth at the 2004 Games in Athens, clocked a season’s best 49.87, just ahead of the Jamaican’s 49.91.

"I’m feeling very positive, but it was a real fight," said the Russian, who was also the 2009 European indoor champion.

With just the first two automatically moving on to tomorrow evening’s final, there was no room for error in tonight’s three heats, and none emerged with all the medal contenders advancing.

The round began with a showdown between Christine Ohuruogu of Great Britain, the reigning Olympic champion, and American Sanya Richards-Ross, the 2008 bronze medallist and 2009 World champion. The American went out hardest, had a clear lead by midway and cruised through the line unchallenged, crossing in 50.07.

By contrast, Ohuruogu ran a conservative first half then gradually accelerated midway through the turn to enter the straight in second, just ahead of Jamaican Rosemarie Whyte. The Briton then surged over the final 60 metres, eating up much of the American’s advantage. Ohuruogu’s time, 50.22, was a season’s best by a whopping 0.20, but still nearly a full second slower than Richards-Ross’s best this season.

"That run was great," said Richards-Ross, who’s clocked 49.28 in 2012. "I didn’t think I had that much cushion coming home. Now I need to rest up and be ready for tomorrow’s final. I need to execute my own race. In Beijing I didn’t do my own race and now I have that opportunity."

There were no surprises in the second heat, either, with World champion Amantle Montsho of Botswana and USA’s No. 2 Francena McCorory crossing the line virtually side-by-side, 50.15 the African champion’s time, 0.04 ahead of the runner-up.

Montsho, who lowered her own national record to 49.54 at the African Championships, carried a slight lead into the final turn, with McCorory running even at the top of the straight.

"I just wanted to run a good time today and qualify for the final," said Montsho, who is aiming to become the first Olympic 400m champion from Africa.

Jamaicans Williams-Mills and Whyte advanced on time to round out the field for the final.

Bob Ramsak for the IAAF