Tyson Gay ran the fastest 100 meters in history under any conditions, winning the final in a wind-aided 9.68 seconds at the US Olympic track and field trials in Eugene, Oregon.
Gay booked his 100-metres ticket to Beijing with the victory, which came with a 4.1m/sec tailwind. Water Dix was second in 9.80 with Darvis Patton third in 9.84 to book Beijing berths.
Travis Padgett missed out in fourth on 9.84.
While not legal for world record considerations, the time was faster than the 9.72 world record set May 31 in New York by Jamaican Usian Bolt, which broke Asafa Powell's previous world mark of 9.74.
"It's going to be a very exciting Olympics," Gay said. "Everybody knows Usain Bolt is the world record holder. I'm running well. Asafa's getting healthy (after a chest injury) and Walter and Darvis are running well."
Gay, who was second to Bolt in New York, left the blocks well and seized the lead at 50 meters, then powered to the finish to ensure his showdown in Beijing with Bolt and Powell at the Bird's Nest Stadium.