Republican rivals Rick Perry and Mitt Romney exchanged sharp blows over who has the better job-creating record on Wednesday in a fiery presidential candidate debate that will help shape the 2012 race.

Perry, the Texas governor and new front-runner for the Republican presidential nomination, wasted little time in attacking his main rival, former Massachusetts governor Romney, at the Ronald Reagan presidential library, a shrine to the iconic Republican president.

Their battle largely overshadowed the six other candidates at the event and was proof that the Republican campaign is increasingly a two-man contest.

Buoyed by support from activists in the conservative Tea Party movement, Perry has relegated Romney to secondary status in opinion polls since entering the race less than a month ago.

Perry came under heavy fire on a number of fronts, forcing him to defend his record in Texas as Romney and others tried to damage his top status but he did not appear to make any serious blunders.

Romney gave a steady performance as well and sought to raise questions about some of Perry's conservative positions, such as Perry's belief that the Social Security program for the elderly is a failed "Ponzi scheme."

Economic Records

Their main fight was over who has the better economic record — the main issue in the campaign as the country reels from 9.1 percent unemployment.

The Texan charged Romney with having one of the worst records creating jobs in Massachusetts in history.

His attack sought to undermine the underpinning of Romney's campaign to convince Americans he can handle the U.S. economy better than struggling Democratic President Barack Obama.

"As a matter of fact, we created more jobs in the last three months in Texas than he created in four years in Massachusetts," Perry said of Romney.

"Wait a second," Romney interjected when moderator Brian Williams of NBC News sought to ask another question. He said Perry benefited from vast reserves of oil in a state that has no income tax.

"Governor Perry doesn't believe that he created those things," Romney said. "If he tried to say those things, it would be like Al Gore saying he invented the Internet. The reality is there are differences between states. I came into a state that was in real trouble... I'm proud of what we were able to do in a tough situation."

Democrat Gore was forced to defend himself during the 2000 presidential campaign for saying he helped create the Internet.

Perry would have none of it, comparing Romney to Democrat Michael Dukakis, the former governor of Massachusetts who lost the presidential campaign in 1988 to Republican George H.W. Bush.

"Michael Dukakis created jobs three times faster than you did, Mitt," he said.

The exchange showed Perry plenty capable of defending himself among rivals trying to knock him off his perch as the leading Republican in the race to take on Obama in 2012.

"I kind of feel like the pinata here," Perry said when Republican Representative Michele Bachmann of Minnesota questioned Perry's executive order to vaccinate sixth grade students against a sexually transmitted disease.

The event was the first in a series of debates in the next six weeks likely to help define the Republican race.