By Mitch Phillips

RIO DE JANEIRO (Reuters) - Gwen Jorgensen is poised to become triathlon's first real crossover star after her Olympic victory on Saturday propelled the American from the sporting backwaters to front-cover status.

Jorgensen has been the dominant force in women's triathlon for two years but ITU circuit wins in far-flung corners of the world meant she remained well under the radar in a country awash with world-class talent in sports that dominate the airwaves.

While triathlon names such as Mark Allen and Dave Scott pricked the American public consciousness through their prodigious achievements at the Hawaii Ironman in the 1980s and 1990s, the shorter version of the sport has always been something of a niche attraction.

However, after a crushing performance to out-run Swiss defending champion Nicola Spirig-Hug on Saturday, Jorgensen now has Olympic gold, a first for the country that invented the sport but which has only Susan Williams' bronze in 2004 to show for its efforts since triathlon joined the Games in 2000.

At 30, well-spoken, modest despite her fantastic achievements and an inspirational example to aspiring sportswomen, sponsors are likely to be queuing up, not just for her signature but for a piece of the triathlon action.

Jorgensen already has deals with Asics, Oakley and her former employer Ernst & Young and can count on many more to come.

"I think it will raise awareness and create momentum for a sport with a very strong and avid group of fans and participants," sports marketing expert David Abrutyn of Bruin Sports Capital said.

"Olympic medals are great drivers of sport that don't usually have the stage and scale that the Games provide. 

"The triathlon community is growing rapidly and there is a large segment of weekend participants with strong demographics with a cross-section of male female and strong disposable income.

"In scale it may not rival traditional stick and ball sports, but the more stars perform on global stages like the Olympics the more exposure for the sport."

Jorgensen was a university runner and swimmer and after completing her master's degree in tax accounting looked set for a "normal life" six years ago until USA Triathlon spotted her potential and persuaded her to switch disciplines.

Success was quick to arrive and though her Olympic debut in 2012 ended with a puncture and a crash she was soon top of the tree and went on to put together an unprecedented 13-race unbeaten run that took her to Rio as the hot favorite.

"It's pretty crazy to show up on the day after four years and accomplish what I said I wanted to accomplish for four years," she said after she managed to wipe her finish-line smile off her face.

"It is a huge testament to my husband and my coach; they have invested way more in me than anyone will ever know.

"We work together, so this is as much their medal as it is mine.

"I wanted to get to August 20th, I wanted to cross that line and get the gold medal, so it is pretty incredible that I was actually able to do it."

(Additional reporting by Liana Baker, editing by Meredith Mazzilli)