Tyson Gay won the battle of the US sprint heavyweights at the Diamond League meet here on Friday, overcoming a terrible start to edge Justin Gatlin on the line for victory in 9.99 seconds.
Other stand-out performances came from strong Olympic favourites David Rudisha and Sally Pearson, but Kenenisa Bekele was left ruing his form after a disastrous outing in the 5,000m saw him confirm he would not defend his distance double at the London Games.
Gay left it late to surge past 2004 Olympic champion Gatlin, who clocked 10.03sec, with French hope Christophe Lemaitre finishing third (10.08).
"I wanted to win this race since Gatlin beat me in the US trials," said Gay, the US national record holder and second fastest man of all-time at 9.68sec.
"I made mistakes at the start, but I tried to get it at the end. I was a little bit sluggish, I've got to keep my head down more and push harder."
A first defeat of the season did not dent Gatlin's ever-high confidence levels.
"I won the gold in Athens and the same thing should happen in London," said the 30-year-old who came back from a four-year doping ban in May 2011.
Rudisha clocked an electric 1:41.54, streaking ahead of the field on the coat-tails of regular pacemaker Sammy Tangui in a bid to break his own world record of 1:41.01 set in 2010.
"In perfect conditions I would have broken the record," the Kenyan said of his last race before the Olympics. "This time it wasn't possible because of the wet track, and also the pacemaker could have been a little faster.
"It was simply too chilly for a record."
Pearson also impressed in the 100m hurdles, dominating from the start to win in an extremely rapid world lead of 12.40sec, not far off the 12.28 she raced to win last year's world championships in Daegu.
"I certainly hope so," Pearson said when asked whether she thought she could break the long-standing world record of 12.21sec set by Bulgarian Yordanka Donkova in 1988.
"I'm getting myself ready for the big event, the Olympics. I'm giving 100 percent to get that gold medal and I'd be very disappointed with anything less."
It was a different story for Bekele, the reigning Olympic 5,000m and 10,000m champion, and the world record-holder over both distances.
The Ethiopian track legend could only finish ninth in the 5,000m, almost 9sec adrift of compatriot Dejen Gebremeskel, who sprinted home in a world lead of 12:46.81 in a race being used as an Ethiopian Olympic trial.
Bekele has slowly been coming back to form after spending two years battling a calf injury, but he never looked comfortable at the Stade de France.
"I won't be going to the Games to race the 5,000m," he said. "But I'm not so disappointed because I have my place in the 10,000m.
"I don't have enough training under my belt to go in the 5,000m."
On-form Renaud Lavillenie maintained his impressive winning form, recording a best of 5.77m to win the pole vault in which there were only 14 successful marks as the 10 competitors struggled with the wet runway.
It was the 10th victorious outing in a row for the two-time world bronze medallist who last week retained his European title in Helsinki.
"The performance wasn't amazing but tonight the ranking was more important," he said.
"I would have liked to jump 5.82m but I was tired from the Euros and the weather conditions were bad. Still, I remain undefeated this season."
Puerto Rico's Javier Culson edged world champion Dai Greene in the 400m hurdles, timing a world lead of 47.78sec, with the Welshman clocking a personal best of 47.84.
"I don't consider myself as the Olympic favourite," Culson said. "I'm not the only one - there are other top hurdlers, especially Greene, who will be at home."
Amantle Montsho of Botswana confirmed her world championship-winning form with victory in the 400m in 49.77sec, Britain's reigning Olympic champion Christine Ohuruogu finishing fourth in a season's best of 50.59.
There was another world lead in the women's 1500m, Morocco's Mariem Selsouli racing to a national record of 3:56.15.
