Usain Bolt thundered past a weak field in driving rain to win the 200 metres at the Diamond League meeting in Oslo on Thursday, clocking the year's fastest time of 19.86 seconds.

The Jamaican world record holder, competing over the distance for the first time in 13 months, danced around in the rain as the announcer read out his name before blazing out of the blocks at the gun. He powered away around the bend before cruising over the finish line.

Norwegian sprinter Jaysuma Saidy Ndure was second in 20.43 on the Bislett Stadium track where he previously trained as a club athlete. Mario Forsythe of Jamaica came in third in 20.49.

Asked if he was back in business, a grinning Bolt told a news conference: "I was never out of business. Business was just a little slow for a while.

"The 200m is my favourite event and I'm glad it went well. Now I'm just concentrating on staying injury-free."

Apart from world record holder Bolt, the Gambian-born Ndure was the only other runner in the

field to have previously broken the 20-second barrier over 200m.

With Ndure seated beside him, Bolt said he thought rival Tyson Gay chose not to contest the 200m at the U.S. trials because of injury problems but the Jamaican showman did not want to get complacent.

"With this guy sitting beside me saying he's going to win, I can't (relax). I'm focussed on the guy in the lane beside me all the time."

A day after jokingly declaring that he was good enough to become a Manchester United player once he hangs up his spikes, he further elaborated his desire to play for the English champions rather than Barcelona by saying: "They (Barca) pass the ball too much and I'm more about the speed!"

The weather played havoc with many of the events as athletes tried to avoid a soaking in the heavy showers.

South African Caster Semenya did not find the cool, damp conditions to her liking and seemed to lack power coming off the final bend. She finished third in the 800m despite posting her best time of the season, 1:58:61.

"Now I have to go home and just rectify my mistakes," Semenya, who shot to fame by winning the 800 world title in Berlin in August 2009 before having an enforced break of almost a year after undergoing gender verification tests, told Reuters.

Finland's Tero Pitkaemaeki also suffered, coming fifth in the javelin event with a throw of 80.22.

Germany's Matthias De Zordo struck gold with a throw of 83.94, well ahead of South African Robert Oosthuizen in second on 82.07.

The loudest cheers of the evening were reserved for local favourite Christina Vukicevic, who won the women's 100m hurdles in a season-best time of 12.79. She beat the American pairing of Kristi Castlin (12.95) and Nichole Denby (13.06).