Dix (C) clocked 9.94sec to beat Gatlin\'s 9.95, with Michael Rodgers third in 9.99 Tyson Gay\'s bid for a World Championships 100m showdown with Usain Bolt evaporated as the American withdrew from the event at the US athletics championships. Gay, who owns the fastest 100m in the world this year of 9.79sec, had been expected to be one of the main challengers to Jamaican world record-holder Bolt in the 100m at the World Championships in Daegu, South Korea.
But Gay pulled out of the 100m at the US selection meeting shortly before the semi-finals.
Olympic bronze medalist Walter Dix edged Justin Gatlin to win the men\'s 100m title. Dix clocked 9.94sec to beat Gatlin\'s 9.95, with Michael Rodgers third in 9.99 to book their berths for Daegu.
Gay was not expected to start the 200m on Saturday.
The 28-year-old had said coming into the championships that he was nursing a sore hip and wouldn\'t compete at the longer distance.
\"Tyson has scratched from the 100m,\" said the athlete\'s manager, Mark Wetmore. \"He was unable to stretch because of a hip and adductor problem on his right side.\"
Wetmore confirmed it was the same injury that has bothered Gay for several months.
After a lackluster performance in Thursday\'s 100m heats, Gay acknowledged his hip was bothering him and would require treatment.
Gay has been plagued by injuries since winning the 100m and 200m world titles in Osaka in 2007.
In 2008, he was injured during the 200m at the US Olympic trials and later that year failed to make the 100m final at the Beijing Games.
The following year, he pulled out of the 200m after taking 100m silver behind Bolt at the World Championships in Berlin.
Gay\'s American record of 9.69sec makes him the second-fastest man in history behind Bolt, who holds the world record of 9.58sec.
Friday\'s events are a significant setback to Gay, not only for his world title hopes but also for his 2012 London Olympics challenge.
If he recovers sufficiently, it\'s still possible that Gay could obtain a relay berth on the US World Championships team.
Gay\'s injury woes are also a setback for the US sprint squad as they look to challenging the Bolt-led Jamaicans at the worlds.
\"It\'s a big blow,\" Dix said. \"Tyson at his best is one of the top runners in the world. We\'re going to have to step up.\"