Romney won in Massachusetts, as well as liberal-leaning Vermont and Idaho, where his fellow Mormons make up a substantial slice of the electorate. He also won in Alaska and Virginia, where Santorum failed to qualify for the ballot.

Santorum said his victories in Tennessee, Oklahoma and North Dakota proved he was the best candidate to represent the party's conservative philosophy. "In every state we overcame the odds," Santorum told supporters, noting that he had been consistently outspent by his rivals throughout the campaign.

Newt Gingrich won his home state of Georgia and said he would stay in the race.

With most of the votes counted in Ohio, Romney led Santorum by 38 percent to 37 percent, and TV networks projected he would take the state. Romney ran strongest in and around the state's largest cities, while Santorum carried the rural areas.

Exit polls showed that Ohio voters viewed Romney as more likely to defeat Obama, but thought Santorum was more sympathetic to average US citizens' concerns.

Romney, who built a fortune of at least $200 million as a private-equity executive, has struggled to connect with conservatives and blue-collar voters. A convincing win in Ohio would have put many of those doubts to rest.

Santorum, a former US senator from Pennsylvania, has won support of religious conservatives thanks to his opposition to gay marriage and his views on other hot-button social issues. His controversial comments about birth control and the role of religion have alienated moderate-leaning voters, especially younger women who will be a key constituency in November.

【Romney ekes out win in Ohio】相关文章：

★ Dragon gets global stamp of approval

★ Geithner may discuss Iran sanctions on Beijing trip

★ 'Humans to blame' for rise in shark attacks

★ 经典英语美文：The Trees Outside my Window

★ 25 workers kidnapped in Egypt

★ In reversal, Obama backs lucrative fundraising drive

★ Romney wins New Hampshire

★ 'Control number of mainland births in HK'

★ Iran denies nuke activity at military site

★ Romney wins Iowa by 8 votes