Maguire won the European Open and UK Championship in 2004

Maguire fell 2-0 and 4-3 behind but made six out of the 14 half-centuries in the match in his fightback that included a 52 in the decider.

Meanwhile, Irishman O'Brien battled back from 2-1 down to record a 6-3 win over home favourite Mark Allen.

O'Brien is in his first ranking final since winning the 1999 British Open.

"I took the game by the scruff of the neck at 2-2 and had three good breaks," said the Irishman.

"I could have won it 6-2 but missed a tricky red on 36, but luckily I got my chance in the next frame.

"I was very nervous at the interval. I felt it was a long day, but after the interval I settled down and felt much better.

"It's great to have a few lean years and then be back in the mix with the chance of winning a title again."

Maguire, 26, said he was delighted after coming out on top following a superb tussle with Murphy.

"That has to be one of the best matches I've ever played in," said the 2004 UK champion.

I played well enough to win but for a couple of mistakes Shaun Murphy

The Scot said it was vital Murphy was never given more than a two-frame advantage.

"I just had to stick in there," said Maguire. "I got off to a terrible start, I was very nervous and doing silly things at 2-0 down. I looked as if I was going 3-0 down.

"I think if I'd gone 3-0 down it was going to be an uphill struggle all day.

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"But I just nicked a couple of massive frames, and it's obviously made the difference at the end."

The 26-year-old added: "It's brilliant to be in the final. I can just relax now and look forward to the match.

"I'll be up for it 100%. In my last three matches I've been fighting against myself; I've wanted to stamp my authority, because it's still early on in the season."

Murphy, the 2005 world champion, was left to rue missing out on a fourth ranking final.

"I'm very disappointed; I played well enough to win but for a couple of mistakes," said the 25-year-old.

"We took each other's best punches. But at 4-3 ahead, I had a green into the yellow pocket - and I didn't know what to do.

"I leave Belfast happy, because I'm playing well and have had a consistent start to the season. But I'd rather be in the final."