Jamaica's Shelly-Ann Fraser-Pryce surged to the women's 100m gold medal in 10.75sec to retain her Olympic title.The 25-year old beat Carmelita Jeter, the 32-year old world champion, from the USA who took silver in a time that was just 0.03 slower than the Jamaican. Veronica Campbell-Brown, Fraser-Pryce's compatriot, took bronze."I went out there and I couldn't think about it before," said the Kingston-based Fraser-Pryce. "I knew it just had to feel right."Jeter described it as "a power-filled final". "I'm just glad I got the finish line," she said. "I hope I represented the USA. It was my first Olympics. I ran a season best and I got a silver."In the semi-finals the two countries traded blows in the centre lanes. Jeter scored for the USA, winning a hard-run first semi-final against Campbell-Brown in a time of 10.83. Eight minutes later Fraser-Pryce equalled the score, beating Allyson Felix into second place in a time of 10.85, easing over the line with a fluent finish.In other races, the reigning 400m Olympic champion Christine Ohuruogu, who was raised in Newham less than a mile from the stadium, delivered a powerful 400m semi-final, coming second in her race to qualify in 50.22. It was her quickest time of 2012 but six of the women she will face in the final ran faster.In the 400m hurdles semi-finals Dai Greene, the Llanelli-born world, European and Commonwealth champion, squeaked into Monday night's final as the seventh-fastest qualifier after finishing fourth behind the 2004 Olympic champion, Félix Sánchez of the Dominican Republic, who won the heat in 47.76, the fastest time run this year.Green said he was "devastated" by his performance. "I feel like I've let everybody down," he said. "I should be able to do better than that. I know I'm better than that. I shouldn't be making the final that way."The medal favourite Javier Culson, 28, from Puerto Rico qualified second.Great Britain's male 400m runners, meanwhile, swept into Sunday night's semi-finals. Nigel Levine, the Trinidad-born runner coached by Linford Christie, went through in 45.58 and his stablemate Conrad Williams qualified from a heat that was missing the reigning Olympic champion, LaShawn Merritt, who withdrew with a hamstring injuryin 46.12. The Croydon-born Martyn Rooney, sixth in Beijing, was the fastest of the British qualifiers with a 45.36 second place but later said he felt "rusty".Team GB's Holly Bleasdale, 20, Blackburn's emerging pole vault star, qualified for Monday night's final in fourth place, clearing 4.55 at the second attempt."I felt really good but I was very nervous," she said. "I never felt something like that in my entire life, but the crowd lifted me."Her British rival Kate Dennison, 28, was knocked out after her final attempt to clear 4.40m failed when her pole sprang her back on to the runway. Eilish McColgan, daughter of the former 10,000m world champion Liz, also fell short in the heats of the 3,000m steeplechase. She competed after being hit by a stolen car while on a training run at Team GB's training camp in Portugal.