World number one Tyson Gay powered to a dominant victory in the 100m final at the Norwich Union London Grand Prix.
Gay is the leading 100m runner this season with a time of 9.84 seconds
Gay cruised home in 10.02 seconds ahead of Francis Obikwelu and Britain's Marlon Devonish and Craig Pickering.
Mark Lewis-Francis staked his claim to the third 100m place in Britain's World Championship team, finishing fifth in 10.31 with rival Tyrone Edgar seventh.
Jason Gardener failed to reach the final as he trailed fourth in his heat - his last 100m race on UK soil.
The 31-year-old could, however, still be selected for the world relay team.
He told BBC Sport afterwards: "The management want a fit, healthy and fast Jason Gardener travelling to Osaka and there's no way I'd want to go unless I can give a good performance for the team."
Lewis-Francis, who finished third at the UK trials, hoped he had done enough to convince the selectors he is worthy of an individual 100m spot in Japan.
I've proven I am a championship performer and I can get in good shape for the Worlds
"I'm not going to get too excited," said the 24-year-old. "I hope I've come out and done enough.
"That was probably my worst race of the year, I false-started and I just ran it but I felt strong."
The British sprinters failed to produce a rousing send-off in the closing 4x100m relay at Crystal Palace.
Gardener had safely passed the baton to training partner Pickering, who tried to make up ground but failed to transfer to Devonish and their race was over.
Gardener is looking for a place in the six-man relay squad and selectors will have to think carefully as expectations of a 4x100m medal in Japan are high.
The meeting was the last chance for British athletes not yet selected for this month's Worlds in Osaka to stake their claim before the team is finalised on Monday.
Laura Turner claimed the women's 100m in 11.37 seconds ahead of UK champion Jeanette Kwakye.
Both athletes were hoping to secure their spots at the Worlds but Turner's career-best winning time was still below the required qualifying 'A' standard of 11.30.
Britain's World Youth champion, Asha Philip, finished fifth and could be included in the relay squad for Japan.
Tim Benjamin looked to have done enough for an individual 400m spot as he produced a season's best 45.28, his fastest time for two years.
The Welshman finished fifth while Olympic champion Jeremy Wariner poured on the pace to overhaul fellow American Lashawn Merritt on the home straight to win in 44.05.
"I put a lot of pressure on myself as I've not been running great," said Benjamin, who beat Andy Steele - winner of the British trial race last weekend in Manchester.
"I hope that is enough to get me to Osaka. I am getting back to my best and I think I can find a sub-45 run from somewhere."
Nicola Sanders also continued to improve after an Achilles problem, recording a season's best of 50.97 in the 400m.
Becky Lyne will also be wondering if she has done enough for the selectors to give her the last pick in the 800m.
The European bronze medallist ran a season's best of two minutes 00.86 seconds, but was just edged into fifth by Jenny Meadows, who also wants to join Marilyn Okoro and Jemma Simpson in Japan.
Kluft was making just her second outdoor appearance in the UK
"I really do feel I can get in good shape for the Worlds," said Lyne, who has been struggling with injury.
"I've proven I am a championship performer and I'm making big strides."
Triple Jumper Tosin Oke improved his chances of joining Phillips Idowu on the runway in Osaka as he rode his luck to produce a personal best.
The 26-year-old Londoner disputed the foul call he received on his second jump and was rewarded with a personal best of 16.86m, which excedes the qualifying 'B' standard of 16.70m.
Idowu, who pulled out of last weekend's trials with a back problem, also delivered some good news as he watched from the stands.
"My injury has recovered quite well and I'm confident I'll perform well in Japan," said the Commonwealth gold medallist. "I'll try and find another meet before then too."
Chris Tomlinson continued his run of good form in the long jump, winning the competition with his final jump of 8.16m.
Olympic gold medallist Veronica Campbell was in impressive form as she cruised to an emphatic win in the 200m in 22.55 seconds.
There was another Olympian in the race - heptathlete Carolina Kluft - but the Swede came home last as the non-specialist sprinter in the field.
Jamaica's Usain Bolt recovered from a slow start to power to victory in the 200m, holding off a fast-finishing Wallace Spearmon to win in 20.06.
The Britons trailed home well short of the required qualifying mark of 20.59, with Luke Fagan (21.11) fourth from Alex Nelson (21.11) and Christian Malcolm (21.19).
UK Athletics selectors have yet to pick a representative for the 200m.
Jo Pavey came through a competitive 3,000m as final preparation for her 10,000m tilt in Osaka.
The Devon runner was overtaken by American Lauren Fleshman on the last lap and just failed to close her down with a sprint finish, crossing the line second in 8:44.13.
Stephanie Twell, 17, proved her future credentials as she produced a personal best of 8:53.34.