American Justin Gatlin continued his fine Diamond League form by winning the 100m in 9.78 seconds in Monaco.
The 33-year-old followed up his time of 9.75 in Lausanne last week with an equally impressive display ahead of next month’s World Championships.
Gatlin, who has served two doping bans, is now unbeaten in 23 races.
American Tyson Gay finished second in 9.97 ahead of France’s Jimmy Vicaut with Britain’s Chijindu Ujah fourth in 10.08.
With world and Olympic champion Usain Bolt still recovering from injury, Gatlin looks in ominous form ahead of the Worlds in Beijing, starting on 22 August.
Jamaican Bolt still hopes to compete in China and will take part in the London Anniversary Games on 24-26 July.
Gatlin, who won silver at the 2013 World Championships behind Bolt, was never seriously troubled in Monaco after a blistering start and clocked another sub-9.8 time after also running 9.74 in May – the fastest time in the world this year.
The New Yorker had an eight-year suspension halved to four years after testing positive for testosterone in 2006, five years after first failing a drugs test in 2001.