SYDNEY — Uncommon upper-body strength and a new rule added to Greco-Roman wrestling this year combined to make Rulon Gardner a most surprising Olympic champion Wednesday night.

Gardner, from the farming town of Afton, Wyo., not far from the Utah border, defeated three-time defending super heavyweight Olympic champion Alexander Kareline from Russia 1-0 in overtime as a packed house in the Olympic Exhibition Hall looked on in various stages of disbelief. Since competing internationally from the age of 21, the 33-year-old Kareline had never lost.

One of the Russian's wins came two and a half years ago against Gardner, the only other time they met.

But Gardner was more seasoned this time around, after spending the past two and a half seasons immersing himself in the art of Greco-Roman, a form of wrestling not common in the United States, where freestyle wrestling is the predominant style in high schools and colleges.

The basic difference is that in freestyle wrestling you can use your legs for holds and pushing; in Greco-Roman the legs just go along for the ride. Even on takedowns, wrestlers must remain in full contact. No over-the-head body slams in Greco-Roman.

It is a classic, man-on-man discipline that relies heavily on upper-body strength.

It was only after Gardner had graduated from the University of Nebraska and capped a successful collegiate freestyle wrestling career with a fourth-place finish in the heavyweight division of the NCAA championships that heturned to the Greco-Roman style.

In an open meet about five years ago where both disciplines were competing, a coach looked at Gardner's massive chest and the way he could manhandle most opponents when going toe-to-toe.

"You should try Greco," he was told.

Gardner took the advice, easily adapted, and a new Greco-Roman force was born. The Wyoming native moved to Tucson, Ariz., and concentrated solely on the new leg-less technique. This past summer, in what must now be viewed as only a preliminary shocker, he defeated 1996 Olympic silver medalist Matt Ghaffari at the U.S. Olympic Trials to win a spot on America's team in Sydney.

Wednesday night, he became just the third American to win a gold medal in Greco-Roman Olympic history (even though the sport has been around since the beginning of the modern Olympic Games in 1896). One of the other two, Steven Fraser, a coach of this year's U.S. team who won a gold medal at heavyweight in 1984, observed, "This means so much to our program, this means so much to me. It gives us a great lift."