Athletics: Richards cruises past Ohuruogu to keep eyes on prize

It was billed as a showdown, but the meeting of the new 400 metres world champion Christine Ohuruogu and world No 1 Sanya Richards turned out to be more of a let down here last night as the Briton finished a weary fourth behind her US rival.

Ohuruogu could only manage a time of 51.32sec, almost two seconds slower than her winning effort in Osaka earlier this month, as Richards, who missed out on racing over a single lap in Japan thanks to a below-par performance in the US trials, finished 20 metres clear in 49.36sec, the fastest time in the world this year.

Richards had a double motivation to win here, given that she arrived as one of only three athletes with a chance of sharing the $1m jackpot on offer to those winning their event at all six IAAF Golden League meetings this season.

That share looks very safe given the way Richards, who had to run the 200m in Osaka and finished outside the medals, performed in a re-vamped Letzigrund Stadium that has been made ready to host games in next year's European Football Championships.

The three $1m contenders became two in the course of the night as Richards' compatriot Michelle Perry lost in a 100m hurdles won by Sweden's Susanna Kallur in 12.66sec. The prize is now between Richards and Russia's Yelena Isinbayeva, who won the pole vault with a relatively sedate 4.80m.

The American, running one lane inside Ohuruogu in lane four, had passed the labouring Briton within 50 metres and there was never any suggestion that she would be challenged.

Ohuruogu, who has admitted that life since winning her title has been " up and down" because of criticism following her return to the track after a one-year suspension for missing three doping tests, appeared almost embarrassed afterwards as she reflected upon what she described as a " disappointing" performance.

"I felt exhausted," she said. "I knew she was going to do what she did, but I couldn't respond. It was very hard out there. When I crossed the line, I thought 'Oh no.' It doesn't matter – but it does matter. I know I am as good as she is when I get myself back into proper shape."

Despite her performance, the 23-year-old University College London graduate is determined to see out a season that only began less than a month ago by racing at the remaining Golden League meetings in Brussels and Berlin before going on to a lucrative race in Shanghai.

Ohuruogu was one of many high-achievers in Osaka who found this meeting hugely challenging. That was nowhere more evident than in the 100 metres, which Asafa Powell, the world record holder, had avoided and from which the world 100m and 200m champion Tyson Gay had withdrawn earlier in the day citing a sore hamstring, although he remained in the lists for the concluding relay event, which the US world champions won with ease in 38.40sec with Gay running the third leg.

The diminished 100m was won by Portugal's double European champion Francis Obikwelu in 10.17sec, with Marlon Devonish, one of three British world sprint relay bronze medalists in the race, third in 10.20sec, the same time as second-placed Jaysuma Saidy Ndure of Norway. Devonish's colleagues Craig Pickering and Mark Lewis-Francis could only manage seventh and eighth place respectively.

Mo Farah finished fifth in a 3,000m won by the world 1500 and 5,000m champion Bernard Lagat in 7min 33.51sec, the Briton crossing the line in 7min 41.86sec.

Xavier Carter, unable to compete in the World Championships because of injury, outran Jamaica's world silver medallist Usain Bolt to win the 200m in 19.92sec.

It seemed as if the immutable law of the post-World Championship event was coming to pass – but Kenya's Janeth Jepkosgei, who won the 800m in Osaka, demonstrated that it was not necessarily so by running clear to win in 1.59.03.