A strong wind cost China's Liu Xiang a share of the 110 meters high hurdles world record at the Prefontaine Classic Diamond League meeting on Saturday.
The 2004 Athens Olympic champion won the race in 12.87 seconds in an eye-popping performance in the lead-up to the London Olympics.
The time equaled Cuban Dayron Robles' 2008 mark but did not count as a joint record because he was assisted by a gust measuring 2.4 meters per second, just above the allowable limit of 2.0.
Liu's fastest official time remains 12.88, set in 2006, and which stood as the word record for two years.
U.S. world indoor champion Aries Merritt finished second on Saturday in 12.96 with world outdoor champion Jason Richardson third in 13.11.
British world champion Mo Farah also impressed, winning the men's 5,000m in 12 minutes 56.98 seconds, the fastest time in the world this year.
Ethiopian world record holder Kenenisa Bekele, still rounding into shape from a calf injury, was fourth in a season best 13:01.48.
Former world champion Allyson Felix destroyed a solid 200m field, sprinting home in 22.23 seconds, while Wallace Spearmon claimed the men's race in 20.27
Earlier, Olympic 400m gold medalist LaShawn Merritt and 2004 Athens 100m Justin Gatlin both sped to victory.
Merritt ran down world champion Kirani James to win the 400 in 44.91 seconds.
James had run under protest after false starting. The protest was later dismissed, allowing Chris Brown of the Bahamas to be promoted as runner up in 45.24.
South African double amputee Oscar Pistorius, who is still seeking to qualify for the Olympics, finished last of the eight starters in 46.86.
Gatlin, undefeated this season, took the 100 dash in 9.90 seconds after a sluggish start, with Jamaican Nickel Ashmeade second in 9.93.
The times were well off the season-leading 9.76 Jamaican world record holder Usain Bolt set in Rome on Thursday.
Olympic bronze medalist Walter Dix was fourth in 10.04.
(Editing by Julian Linden)
(This story has been corrected to fix typo in headline)