A flat-looking Usain Bolt raced his worst 100m in three years here on Friday, still managing to claim victory after he recovered sufficiently from a dreadful start and a limp drive phase.
The Jamaican double Olympic sprint champion clocked 10.04 seconds, some distance off the 9.7sec time he was seeking to build on his season-opening 9.82sec earlier this month.
A false start played its part, throwing a distinctly average field into automatic play-safe mode.
Into a -0.8m/s headwind, Bolt grimaced his way from the 50m mark and did enough to beat home veteran Kim Collins of St Kitts and St Nevis (10.19sec) with American Darivs Patton third (10.22).
"I haven't run that badly since a meet in Canada in 2009," said a noticeably downbeat Bolt, also the world record holder in both the 100 and 200m (9.58 and 19.19sec).
"That's reality, a very bad day at the starting blocks. When I was in the back warming up, I did some starts and I was flying.
"But I ran out and didn't get going, couldn't generate speed in middle of race so I had to work hard to get some speed up."
Elsewhere on the track, defending Olympic champion Pamela Jelimo of Kenya fired a broadside at South African pretender Caster Semenya with a convincing victory in the women's 800m.
Jelimo, also the newly-crowned world indoor champion but who missed almost three years of competition after her Beijing Games triumph through injury, dominated the race to win in 1min 58.49sec, with Semenya in second in 2:00.80.
"Of course everybody wants to do their best because it is so close to the Olympics," said Jelimo, whose kick at the bell opened up too much air between her and the chasing pack.
"I do not run against anybody, including Caster. I just focus on myself. I want to try and do even better next week."
Semenya, with doubts over her real gender long buried in her past, left her push for the line too late.
The South African, who shot to fame when she won the world title in Berlin in 2009 but was then sidelined for 11 months during a probe into her true gender, settled in at the back of the pack and only kicked with 150m to go.
By that stage, Jelimo had kicked and there was too much for Semenya, now coached by Mozambique running legend Maria Mutola, to make up.
"I'm quite happy with my preparations for the Olympics. I now just need to build up more speed for competition," said Semenya.
There was more South African disappointment when double amputee Oscar Pistorius raced a horrendous 400m in his ongoing bid to nail qualification for the able-bodied Olympics.
The 25-year-old South African, who runs with carbon-fibre artificial 'blades', came in a sorry eighth and last in 47.66sec, 2.54sec off American winner LaShawn Merritt and far away from the 45.70 he needs to run to ensure his participation at the London Games.
"The time was so bad!" Pistorius said. "I don't know what to say. I can run that fast at the end of a tough training session or straight after getting up out of bed in the morning."
The stand-out field performance was from Frenchman Renaud Lavillenie, who made his return to competition in impressive style by setting a new world lead and meet record of 5.90m in the pole vault in blustery conditions.
"It was a great start to the season," beamed Lavillenie. "I'm not unbeatable, but it's a good response to (Bjorn) Otto", who had set the previous world lead of 5.83m on Wednesday.
Jamaica's two-time Olympic champion Veronica Campbell-Brown won the women's 200m in 22.38sec, and American Wallace Spearmon the men's equivalent in 20.14sec.
American Dexter Faulk claimed the 110m hurdles in an impressive 13.13sec.
And Barbora Spotakova gave home fans something to cheer about, the Czech world record holder throwing a world lead and meet record 67.78m to win the women's javelin.