LONDON – Australian world champion hurdler Sally Pearson suffered a surprising defeat at the London Diamond League meeting Saturday on a day of upsets at a rain-soaked Crystal Palace. Olympic favorite Pearson, the 2011 world championship gold medallist, was beaten in the 100m hurdles for only the second time in 34 races as American Kellie Wells stormed home in 12.57secs. “I'm feeling really good,” said Wells. “It's not about racing, it's about executing – I know that if I execute I'm going to be hard to beat,” the 29-year-old added. Pearson, the fastest woman in the world this year after clocking 12.40sec in Paris earlier this month, finished second in 12.59sec with American Virginia Crawford third in 12.74sec. The event had earlier seen a tearful exit from controversial British sprinter Tiffany Porter, with the American-born athlete finishing last in her heat citing an unspecified fitness problem. Pearson's shock first loss of the season had followed a similar upset in the women's 100m, Nigeria's Blessing Okagbare scoring a surprise victory after upstaging a strong field which included Olympic champion Shelly-Ann Fraser-Pryce of Jamaica and reigning world champion Carmelita Jeter. Okagbare, who had dipped under 11 seconds in the heats, then held off the strong finishing American Jeter to cross in 11.01sec, with Jeter finishing in 11.03 and Tianna Madison third in 11.13sec. The final event of the day saw Britain's defending Olympic 400m champion Christine Ohuruogu indicate she is hitting form at the right time with victory over reigning world champion Amantle Montsho of Botswana. Ohuruogo overhauled Montsho in the final few meters of a race held in torrential rain with a season's best of 50.42 sec. Montsho finished in 50.56sec with Rosemarie Whyte of Jamaica third. Elsewhere Saturday, Frenchman Christophe Lemaitre produced a superb display to take the 200m with the third fastest time in the world this year of 19.91sec. Lemaitre fought off a strong challenge from the Netherlands' Churandy Martina down the home straight with Marvin Anderson of Jamaica in third. Reigning 400m world champion Kirani James signalled a return to form with a confident victory after a season which has seen the 19-year-old from Grenada keep a low profile. James timed his run to perfection to cross in 44.85sec, ahead of the Bahamas Chris Brown in 44.95sec and Tony McQuay of the United States, 45sec. Poland's Adam Kszczot won the 800m, although his time of 1:44.49 will not alarm the absent David Rudisha of Kenya, the world record holder and reigning world champion who will start as the favourite at the London Olympics. The men's mile was won by Silas Kiplagat of Kenya in a time of 3:52.44, with Britain's Ross Murray trailing by 0.33sec. Caleb Ndiku was third with 3:53.15. World 5,000 meters champion Mo Farah underlined his credentials Friday. Farah, who also won world silver in the 10,000 in Daegu last year, won in 13 minutes, 6.04 seconds. American Tyson Gay made a poor start in the men's 100 final but came through in the final 20 meters to win in a time of 10.03 into a headwind. Injury problems also struck China's 2004 Olympic champion Liu Xiang who had to pull out of the final of 110 meters hurdles after tweaking his back while warming up. With Liu sidelined, world indoor champion Aries Merritt came up with a dominant display to win in 12.93 and equal his world leading time. Britain's Perri Shakes-Drayton provided some early cheer for home fans, winning the women's 400 hurdles ahead of European champion Irina Davydova in a personal best of 53.77, a time that took her to second in the world this year. World champion Dai Greene could not provide the crowd with a British double in the event as Puerto Rica's Javier Culson maintained his unbeaten record for the season, winning the men's 400 hurdles in 47.78 to equal his world leading time. Greene snatched second place ahead of Olympic champion Angelo Taylor in 48.10. Kenyan double world champion Vivian Cheruiyot showed why she is a medal favorite at the Olympics by winning her 11th successive 5,000 meters race. Pole vaulter Steve Hooker's problems continued after the Australian Olympic champion did not register a height, failing three times at 5.40 meters in the difficult conditions. It was not much better for Olympic favorite Renaud Lavillenie of France, whose only clearance was at 5.40. The event was won by Germany's world indoor silver medallist Bjorn Otto with a height of 5.74. American Chaunte Lowe won the women's high jump with a leap of 2.00 meters and Australian Mitchell Watt took the men's long jump with 8.28 meters, two centimeters further than Britain's Chris Tomlinson. – Agencies