Cycling great Lance Armstrong returned to sporting competition on Sunday, finishing second in the Panama 70.3 half ironman.
The 40-year-old American retired from professional cycling last year following a career in which he overcame testicular, brain and lung cancer to win the Tour de France seven times in succession.
Texas-born Armstrong competed in amateur and professional triathlons as a teenager, before focusing solely on cycling.
Making a return to the triathlon, he finished second following a 1.9km swim, 90km cycle and 21km run in Panama City.
"I need a challenge in my life," he said.
"I need some stuff to do. I like to train. I like to suffer a bit and today was little over the top, but it's great to be back."
Armstrong, who clocked a time of three hours 50 minutes 55 seconds, led going into the final leg of the event, before being overtaken late by New Zealander Bevan Docherty (3:50.13), a gold medal winner in triathlon at the 2004 Athens Olympics.
"This was absolutely awesome," Docherty said.
"That was one hard race, I wasn't sure what to expect but Lance really pushed me."
"This is my first half ironman in 12 years so I wasn't too sure how to pace myself so I just went out hard and seemed to pace quite well. I got my second wind before a k (kilometre) to go and managed to catch Lance but that last k really hurt."
Australian Richie Cunningham (3:52.59) was third.
Armstrong is set to compete in Ironman France this June, in an attempt to qualify for October's world championships in Hawaii.
The Ironman event involves a 3.86km swim, 180.25km bike race and 42.2km run, double the distance of a regular triathlon.
Earlier this month US federal prosecutors closed an investigation into allegations of drug use levelled at Armstrong by former team-mate Floyd Landis, with no charges laid.