Pennsylvania Republican Sen.-elect Pat Toomey delivers his victory speech early today to supporters at his election night headquarters in Fogelsville after defeating Democrat Joe Sestak.

PHILADELPHIA — Pat Toomey, the Republican conservative whose popularity scared Arlen Specter from the GOP, was elected to Specter's Senate seat Tuesday in one of the most hotly contested races in the nation.

Toomey, a 48-year-old former congressman, investment banker and restaurateur from the Allentown area, defeated Democratic Rep. Joe Sestak after hammering him on his liberal voting record and his ties to House Speaker Nancy Pelosi and President Barack Obama.

With 99 percent of precincts reporting, Toomey had 51 percent to Sestak's 49 percent, winning by fewer than 75,000 votes out of nearly 3.9 million cast.

Toomey, a strict free-market advocate, will take office with an eye toward cutting spending and deficits and repealing, or at least making drastic changes to, the sweeping federal health care law that Obama signed in March.

"We've got to remember a very fundamental and important truth, and that is that governments don't create wealth," Toomey told exuberant supporters. "Wealth and prosperity come from men and women who get up every day and go to work."

Sestak, 58, now in his second term representing a suburban Philadelphia district, is a former Navy vice admiral who commanded an aircraft carrier group in war after the Sept. 11, 2001, terrorist attacks.

It was the prospect of a tough challenge from Toomey that led Specter to quit the Republican Party and become a Democrat in 2009. But it was Sestak who put an end to Specter's 30-year Senate career by defeating him in a shocking primary upset last spring.

Tuesday's balloting capped a bare-knuckled campaign in which voters were inundated with tens of millions of dollars in TV and Internet attack ads and campaign fliers as they decided on a successor to Specter.

The two candidates are ideological opposites who portrayed each other as too extreme for Pennsylvania.

Toomey sought to tap into voter dissatisfaction over unemployment and the shaky economy to argue that Sestak, and his support for Obama's policies, were to blame.

Sestak worked to convince voters that he was stuck cleaning up an economic mess made by Toomey and the Bush administration's policies. He cast Toomey as an apologist for Wall Street whose zeal for tax-cutting and deregulation helped cause the recession and sent jobs overseas.

The race cost more than $50 million, including spending by the candidates, political parties, unions and national business advocates in the general election and the bruising Democratic primary.