Tyson Gay produced a stunning 150m run in Manchester to send a clear message to rival Usain Bolt for the new season.
The American ended the last campaign as world number one and looked in hot form at the Great City Games, with the World Championships three months away.
Gay, 28, clocked 14.51 seconds in the rain, just 0.16s slower than the mark set by Bolt at the same event in 2009.
American Allyson Felix and Britons Andy Turner and Jessica Ennis impressed at Sunday's street meeting on Deansgate.
The sprinting performance by the former 100m and 200m world champion capped off an action-packed day in Manchester.
Described as Manchester's 'Great Day of Sport', Ethiopian legend Haile Gebrselassie and Britain's Helen Clitheroe began Sunday with victories in the 10km Great Manchester Run, followed by wins by .
And then it was time for some of the world's top athletes to turn on the style despite the Manchester drizzle.
Gay was the star of the show as he breezed past his opponents, that included Britons Marlon Devonish and Christian Malcolm, in the 150m race.
The American had set a world best for 200m on a straight track with 19.41s in Manchester last year and was looking to beat the world mark of 14.35secs in the 150m set by triple Olympic champion Bolt two years ago.
Despite falling short of his Jamaican rival, the time of 14.51 was still a tremendous performance considering it was his first outing of the season and the damp and cold weather conditions.
After clocking 8.8 seconds for the 100m stretch between 50m and the finish, Gay told BBC Sport: "I've missed a lot of training this year because of a couple of little niggles and injuries so I'm pretty impressed with my performance.
"I'm feeling OK. I'm a little bit sore, but nothing major. I'm feeling pretty good. I came through the first 100m in 9.91, that's kind of where everyone else is in the world right now so that's now bad.
"I'm satisfied with my time, I think it's pretty fast, but I've just got to stay healthy and be ready."
Britain's Andy Turner, European champion, produced two stunning victories in the 110m and 200m hurdles to blow away American rivals Terrence Tramell and Bershawn Jackson, as well as Olympic 400m hurdles champion Felix Sanchez.
World and European heptathlon champion Ennis also looked in fine form and was in good spirits after competing for the first time since an ankle tendon problem ruled her out of the European Indoor Championships, leaving her unable to run for seven weeks.
A time of 12.88s for the 100m hurdles behind specialists Ginnie Crawford and fellow American Danielle Carruthers was an exceptional showing, although a 17.40s to finish behind GB team-mate Abi Oyepitan in the 150m was less than convincing.
Remaining injury-free was top priority though and the 25-year-old said: "One massive positive to take from the day is that my ankle feels good.
"It's a bit of a relief to be back in competition and I'm just excited about the season now. If someone had said two weeks ago that I would be in Manchester running that sort of time in the hurdles, I would have been very happy with that.
"So I'm glad I did it and now I can move on. To get into this shape so quickly is quite promising."
The Sheffield-based star will next compete in the javelin in the Loughborough International on Sunday, before heading to Gotzis, Austria for her first heptathlon of the season on 28 and 29 May.
Olympic 400m champion Christine Ohuruogu, another athlete looking to forget an injury-hit 2010, was well off the pace to finish fourth in the 200m in 24.48, with American Felix cruising to victory in 22.12.
Other winners included Mark Lewis-Francis and Jeanette Kwakye in the 100m, and France's Martial Mbandjock in the 200m.