Liu Xiang sent an ominous warning to his main London Olympic rival when a wind gust denied him a share of the 110 meters hurdles world record at the Prefontaine Classic Diamond League meeting on Saturday.
The 2004 Athens Olympic gold medalist stormed home in 12.87 seconds in an eye-popping run that matched Cuban Dayron Robles' mark, set in 2008.
But his performance did not count as a joint record because he was assisted by winds measuring 2.4 meters per second, just above the allowable limit of 2.0.
Robles had been scheduled to run in the same race, but missed the meeting because of visa problems, and Liu said he was not getting carried away with his time.
"Of course I am happy but it is just a race for me. I need to look forward," Liu said.
"I think my start was good, but I think I made some mistakes from the third to the sixth hurdles. Maybe the wind pushed me so much."
The time came hot on the heels of his season-leading run of 12.97 in May, his fastest non winded assisted performance in five years as he continues his comeback from a heart-breaking 2008 leg injury that caused him to withdraw from the Beijing Olympics.
Liu's fastest official time remains 12.88, set in 2006, and which stood as the world 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.
Six other 2012 best performances were set at the meeting, conducted at the same site for the U.S. Olympic trials, starting in three weeks.
They included Kenyan Olympic 1,500 meters gold medalist Asbel Kiprop clocking 3:49.40 to win the mile, U.S. shot putter Reese Hoffa winning in 21.81m and former American world 400m champion Sanya Richards-Ross racing 49.39.
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)