Olympic gold medalist Justin Gatlin was disqualified.
CARSON, Calif. (AP) -- Marion Jones grabbed her warm-up clothes and walked off the track moments before the start of the 100-meter preliminaries at the U.S. track and field championships on Friday, a stunning exit for the woman who once dominated the event.
Moments later, Olympic gold medalist Justin Gatlin was disqualified from the men's 100 for a false start.
It was a staggering few minutes in Day 2 of the four-day meet that will determine the U.S. team at the world championships in Helsinki Aug. 6-14.
Jones, a two-time world champion and 2000 Olympic gold medalist in the 100, has been dogged by doping suspicion for two seasons, even though she never has tested positive for performance enhancing drugs and has vehemently denied ever taking them.
Jones was once the charismatic darling of the sport, winner of an unprecedented five track medals at the Sydney Games.
She took 2003 off to have a baby, and never returned to her old form.
Meanwhile, through associations and accusations by her ex-husband and the founder of the Bay Area Laboratory Cooperative, doping suspicions grew.
Her performances this year made her a long shot to make the U.S. team.
Still, she needed only to have a better time than two of the 18 runners in the preliminaries to advance to today's semifinals.
Jones, running in the third and final heat, took one warm-up run out of the blocks, then walked up and down her lane before going to pick up her clothes from a plastic bucket behind her starting blocks. She walked briskly off the track and left Home Depot Center.
Jones' abrupt departure came hours after her boyfriend, former world record holder Tim Montgomery, withdrew from the men's 100.
"Considering everything that's going on, he just can't concentrate on track and field," his agent, Charles Wells, said.
Gatlin, who had talked at length about his budding rivalry with new world record holder Asafa Powell of Jamaica, was called for a false start based on computer readings of the pressure he puts on the blocks. The field gets one false start, but anyone who has one after that is eliminated.
Gatlin was measured coming out of the blocks in 0.095 seconds, five-thousands of a seconds faster than the 0.100 allowed. In the second heat, Bernard Williams was eliminated by a false start.
Montgomery had no start at all.
He set the world 100 record at 9.78 seconds in 2002, and the mark stood until Powell ran 9.77 last week.
The father of Jones' child, Montgomery is awaiting word on his appeal of the lifetime ban proposed by the U.S. Anti-Doping Agency.
The appeal was heard earlier this month by the international Court of Arbitration for Sport, which has the final word. Montgomery has not tested positive for steroids or any other banned substance, but USADA proposed the punishment based on evidence gathered in the criminal probe of BALCO.
In competition on Friday, Olympic silver medalist Bryan Clay set a world decathlon discus record.
Clay, the heavy favorite in the 10-event competition with the absence of injured Tom Pappas, threw 183 feet, 3 inches to break the world mark of 180-5 set by Razvigor Yankov of Bulgaria in 1979.