Former world 100 metres champion Tyson Gay finished second behind fellow American Justin Gatlin on his return to competition after a one-year doping ban at the Lausanne Diamond League meeting.
Gatlin, the 2004 Athens Olympics gold medallist who was later banned for four years for doping, clocked a season's best 9.80 seconds while Gay clocked 9.93. American champion Mike Rodgers, who has also served a drugs suspension, was third.
I felt very welcomed by my fellow athletes, it's great to make a return with 9.93.
Gay was cleared to compete in the Swiss lakeside city after the international federation decided it would not contest the United States Anti-Doping Agency's decision to halve his ban.
The 2007 world gold medallist tested positive for a steroid at last year's US championships.
"I'm happy to be back on the circuit, I didn't miss a beat," Gay told reporters. "I felt very welcomed by my fellow athletes, it's great to make a return with 9.93."
James sets record
On a perfect summer's evening, Grenada's Olympic champion Kirani James set a personal best of 43.74 seconds in the men's 400 metres to join his American rival LaShawn Merritt on equal fifth place in the all-time list. Merritt finished second in 43.92 seconds.
"The conditions were perfect, the crowd was brilliant, and I am very happy," James said. "I'm very happy to run a national record, it's always something to be proud of. LaShawn was strong and he pushed me."
Frenchman Pascal Martinot-Lagarde clocked a personal best of 13.06 seconds in the men's high hurdles, the second fastest time in the world this year.
In the final event of the evening, Ukraine's Bohdan Bondarenko won the latest battle between the world's elite male high jumpers before failing with three attempts on Cuban Javier Sotomayor's 21-year-old world record mark of 2.45 metres.