Farah is far too good but saves the 'Mobot' for afters

Mo Farah: Won the 5,000m at the Aviva London Grand Prix with a relaxed performance (Reuters)

Mo Farah could have performed his "Mobot" celebration in front of the home-straight gallery at Crystal Palace last night, without risking defeat in his final pre-Olympic test.

Such was the burst of speed he produced when it came to the crunch in a smooth and controlled 5,000-metres performance, he was out of reach of his rivals by the last 100m.

The world 5,000m champion was content to bide his time in the pack until two laps to go, before hitting the front for the first time. Even then he didn't put his foot on the accelerator until the bell, pulling clear of the Ugandan Moses Kipsiro and then the Australian Collis Birmingham with an upping of the pace from the 200m-to-go mark.

The great British Olympic hope crossed the line in 13 minutes and 06.04 seconds, a long way short of his UK-record figures, then went through his "Mobot" routine to please the crowd.

"It went well," Farah said, reflecting on what was essentially a sharpening exercise ahead of the London Games. "I'm in great form. It's important that I work on my speed."

Dai Greene, Britain's other reigning world champion, had to be content with another runners-up place behind Javier Culson, the Puerto Rican whom he beat to the global 400m crown in Daegu last summer. The Swansea Harrier finished second to Culson at the Diamond League in Paris eight days ago and had to dig deep down the home straight last night to do so again, clawing his way past Angelo Taylor, the two-time Olympic champion from the United States.

"It was OK," said Greene, who finished 0.32sec adrift in 48.10sec "I think it was my third-fastest time ever so I can't be too disappointed.

"I've got a few more weeks to get a bit sharper. So I'm looking forward to the Olympic and hopefully I can get one over Culson then."

Behind Taylor, Greene's training partner, Jack Green, continued his steady progress with a personal best of 48.60sec in fourth place.

It was a good night for a good many of the Britons getting ready for the home Games, not least Chris Tomlinson. The Teessider has struggled for form all season but he uncorked an 8.26m long jump to take second place, 2cm down on Mitchell Watt, the Australian who took World Championship silver last year.

There was also a fine 1500m by Laura Weightman, the Morpeth Harrier who has run her way into Olympic team under the direction of the former world mile record holder Steve Cram. The 21-year-old finished fourth in a high-class field in 4min 08.19sec. Hannah England, returning to action after an Achilles injury, brought up the rear, 11th in 4:14.45.

It was also a painful night for Liu Xiang. After winning his 110m hurdles heat, China's world record holder withdrew from the final because of a back twinge.

At the World Junior Champion-ships in Barcelona, meanwhile, the emerging young Liverpudlian heptathlete Katarina Johnson-Thompson won the long-jump title with a wind-assisted 6.81m.