U.S. Republican presidential candidate Mitt Romney was the winner in six of the 10 states that held nominating contests Tuesday, including a narrow victory in the crucial battleground state of Ohio

The win in Ohio over his main rival, former U.S. Senator Rick Santorum, was by a margin of just one percent. Romney also secured primary victories in Vermont, Virginia and Massachusetts as well as caucus election wins in Idaho and Alaska.

Speaking in Boston, Romney predicted that he would eventually win the nomination and face President Barack Obama in the November election.

“Tonight we are doing some counting. We are counting up the delegates for the convention and it looks good. And we are counting down the days until November and that looks even better. We are going to take your vote – a huge vote tonight in Massachusetts – and take that victory all the way to the White House.”

More than one-third of the 1,144 delegates needed to win the Republican nomination were up for grabs on Super Tuesday — more than all of the previous primaries and caucuses combined.

Romney is far ahead in the delegate count and he had hoped “Super Tuesday” would establish him as the inevitable nominee. But he has failed to attract support from working-class voters and religious conservatives, who have flocked to Santorum.

Santorum won Tuesday's nominating contests in North Dakota, Oklahoma, and Tennessee, in hopes of regaining the momentum that helped him win three states in one day in last month. He celebrated his victories during a rally in Ohio, hours before that state's results were announced.

“Tonight it's clear, it's clear, we've won races all over this country against the odds when they thought 'Okay, he's finally finished.' We keep coming back. We are in this thing, we are in this thing not because I so badly want to be the most powerful man in this country. It's because I want so badly to return the power to you in this country.”

Former U.S. House speaker Newt Gingrich won Georgia, the southeastern state he represented in Congress for two decades. He spoke to cheering supporters in Atlanta.

“Let me be very clear. I believe that I am the one candidate who has the ability to debate Barack Obama decisively this fall.”

Representative Ron Paul, who has yet to win a nominating contest, rallied supporters Tuesday in North Dakota with his anti-war stance.

“Because there are a bunch of people up in Washington right now, and other candidates, (who say) that we can't wait until we go into Syria, into Iran. That makes no sense, we can't afford it, it won't help it (the situation), and it won't give us more defense.”

The Republican party will formally nominate its presidential candidate at the national nominating convention in Tampa, Florida, in late August.