A mistimed dip for the finish line cost Tyson Gay victory in the men's 100m Diamond League meet in New York as Steve Mullings claimed first place.
American Gay made a poor start in the wet conditions but produced a powerful second 50m burst to cross the line alongside his Jamaican rival.
But a photo finish awarded first place to Mullings in a time of 10.26secs.
World and European champion Phillips Idowu secured first place in the men's triple jump with a leap of 16.67m.
The 32-year-old's third attempt was 38cm better than Sweden's Christian Olsson, who finished in second place with Leevan Sands of the Bahamas taking third spot.
France's world indoor champion Teddy Tamgho could not find his rhythm in the damp conditions at the Icahn Stadium, finishing down in seventh place with 15.55m.
However, the main event of the day was the 100m showdown between Gay and Mullings, the two fastest men over 100m this year.
But both were forced to endure three false starts, shrinking the field from nine to six competitors running into a stiff wind.
The race burst into life at the fourth attempt as Gay stuttered out of the blocks, in complete contrast to Mullings who took a metre off his training partner inside the first 30m.
But 2007 world champion Gay powered through the second half of the race and looked to have it won - only to dip for the line too early as Mullings timed his finish to perfection.
Asthma sufferer Mullings needed oxygen after his victory to alleviate the pressure around his chest caused by the cold weather.
"I knew Tyson has got a strong finish," said Mullings, who ran 9.80secs to win the Diamond League meet in Eugene. "I just have to get out of the blocks strong."
Gay dismissed concerns that the hip injury which has affected his training schedule was responsible for his below-par performance.
"I was just a little bit sluggish, I haven't been able to really push in practice," he said.
Wales' European champion Dai Greene finished a creditable third in the men's 400m hurdles behind race winner Javier Culson and Olympic bronze medallist Bershawn Jackson.
But Jessica Ennis, recently awarded an MBE in the Queen's birthday honours list, endured a difficult night in the women's long jump and 100m hurdles.
The world heptathlon champion was 45cm short of American Funmi Jimoh's winning jump of 6.48m, finishing down in eighth place while she was off the pace in the hurdles, finishing seventh in a race won by Danielle Carruthers in 13.04secs.
Her British compatriot Tiffany Ofili-Porter came third in the hurdles in a time of 13.11.
Elsewhere, three-time world champion Allyson Felix won the 200m in 22.92secs in an American clean sweep of the top three places.
Two-time women's world high jump champion Blanka Vlasic of Croatia was beaten by Sweden's Emma Green Tregaro, who cleared 1.94m while Vlasic only managed 1.90.
And double-amputee Oscar Pistorius was fifth in the men's 400m in 45.69secs behind race winner Jeremy Wariner.