Usain Bolt targeting new 200 metres world record at London 2012 Olympics

Usain Bolt cruised into tonight's final (GETTY IMAGES)

Usain Bolt believes he can break his own world record after cruising into the 200 metres final with contemptuous ease at London 2012.

While many would already consider the Jamaican superstar a legend for winning triple gold in Beijing and defending his 100m title here on Sunday, Bolt insists he also has to retain his 200m title to achieve such status.

And the 25-year-old looks an increasingly certain bet to do just that, effectively winning his semi-final tonight before halfway and almost jogging down the home straight to win in 20.18 seconds.

Team-mate Yohan Blake was the fastest qualifier after also slowing down markedly in winning the opening semi-final in 20.01secs, but Bolt is certain he will put his training partner in his place once again on Thursday.

"No doubt whatsoever," Bolt said. "I'm ready, this is my favourite event, so I'm looking forward to it. I really pushed myself in the first 70 metres and then I tried to take it as easy as possible. I ran harder round the corner than I have in a long while. The execution was probably 90%."

Asked about breaking his record of 19.19s - set when winning the world title in Berlin in 2009 - Bolt added: "It is a possibility, definitely.

"The track is fast and there are a lot of great competitors. I am looking forward to it. If I put it on my mind you never know if it is going to happen."

Blake, who won the 100m world title after Bolt was disqualified for a false start in Daegu last year and had to settle for silver here, said: "I found myself out in front and I cruised from there. I do a lot of work on the corner to get out in front. Anything is possible in the final tomorrow. It's going to be a good race."

While Bolt and Blake dominated the 200m for Jamaica, it was American athletes who enjoyed medal success on Wednesday evening, winning three of the four gold medals on offer.

The first gold on offer went to Russia's Natalya Antyukh in the 400m hurdles, the 31-year-old just holding off American Lashinda Demus at the finish in a PB of 52.70s - just 0.06 outside the Olympic record.But from then on it was American domination as Allyson Felix won the 200m, Brittney Reese took gold in the long jump and Aries Merritt led a one-two in the 110m hurdles.

Felix had finished second in Athens and Beijing but it was third time lucky as she won in 21.88 ahead of 100m champion Shelly-Ann Fraser-Pryce and fellow American Carmelita Jeter.

"It's just awesome, I've wanted it for so long," Felix said. "This moment is really priceless. I am so overjoyed."

Reese managed just two legal jumps from six attempts, but the first of those was 7.12m in the second round and proved enough to win after Russia's Elena Sokolova was unable to improve on her best of 7.07m, also achieved in the second round.

Janay Deloach continued a great night for the American team by claiming bronze by just one centimetre from Latvia's Ineta Radevica, who jumped 6.88m twice but saw Deloach manage 6.89m in round five.

In the 110m hurdles, Merritt stormed to victory in 12.92s, the fastest time in the world this year and just 0.01s off the Olympic record set by Liu Xiang in Athens in 2004.

Team-mate Jason Richardson took silver in 13.04 with Jamaica's Hansle Parchment taking bronze in a new national record of 13.12s. Defending champion Dayron Robles pulled up injured midway through the final.

"I am so excited, words can't explain how excited I am right now," Merritt said. "People were talking about a world record but 12.92 into a headwind is still pretty impressive. I am happy with that."

PA