Team RadioShack’s Lance Armstrong came out slightly ahead of Ironman triathlete Chris Lieto in their time trial showdown yesterday, finishing between nine and 15 seconds ahead at the end of the 14 mile test.

The informal race against the clock had no prizes on offer but with pride at stake, both riders dug deep to chase the best possible time.

The Twitter-organised challenge saw seven-times Tour de France champion Armstrong go up against 2009 Kona Ironman world championship runner-up Lieto on the famous Queen K highway in Hawaii, part of the Ironman course.

Lieto had the fastest bike split in last year’s race. Armstrong has indicated that he will compete in the Ironman once he retires from road racing, and so the race was a gauge as to how fast top triathletes can be.

“It was close, it was super fast with a big tailwind, plus you had the cars on the highway,” said Armstrong afterwards. “I did 18.35, Chris 18.50, but my average speed was 56 kilometres per hour, so 15 seconds over 18 minutes…for a guy who is used to riding 112 miles, 56 kilometres per hour is pretty fast.

“The first of many? Who knows, maybe we will have a showdown out here in a couple of years.”

Lieto later posted a revised time of 18.44 for his effort, a nine second difference.

Yesterday’s wind-assisted TT confirms what was expected, namely that Armstrong should be quicker than the top triathletes on the bike leg. However Lieto’s small margin of defeat – and the fact that he had earlier done a three mile swim – underlines that if the Texan wishes to challenge for an Ironman title, he will have to work hard on his swimming and running in order to limit any losses in those areas.

As mentioned on VeloNation yesterday, his coach Chris Carmichael confirmed last October that the multiple Tour de France winner would compete in next year’s Kona Ironman world championships, and would have firm goals in mind.

“In 2011, he will be here,” he told Everymantri.com. “He is super psyched. And I think he wants to do more than just win his age group….”

Lieto welcomes triathlon crossover:

In an interview with Slowtwitch.com just over a year ago, Lieto was positive about the possibility of Armstrong doing an Ironman.

“I think it will be great for the sport. It will be fun. Hopefully with us both being on Treks there will be some synergy there. I’d love to give him some advice,. I don’t know how much advice I could give him besides just the experience of doing it. He is phenomenal athlete and I think he will do great. He will be one to watch out for. Anything he does he excels at.”

He said that he expected Armstrong to lose at least five minutes in the water, but to finish the bike leg ahead of everyone else.

“What happens next depends on how much running he puts in,” he said. “He would have a lead on the bike and he would try to run the best he can. The final result would depend on his preparation. I don’t think he will win. [He’d get] top ten, probably. He could do better. It’s hard to say. You just don’t know. It depends on what his goals are and what amount of preparation he puts into it…. If he is going into the race to win, then he will prepare to win. And then the result will be different because he will try a lot harder.

“If it is just to participate and do something for LiveStrong, he won’t have that weight on his shoulders and he will probably finish top 10 or something like that.”

Armstrong’s priority before then is to try to win another Tour de France title. He finished third last year, with Alberto Contador and Andy Schleck proving stronger in the mountains, and Contador also having the edge in time trials.