BALTRAY, Ireland -- Irish amateur Shane Lowry capped off his remarkable debut on the European Tour by winning the Irish Open title on Sunday on the third hole of a playoff against Robert Rock of England.

Lowry, who missed a three-foot putt to win on the last hole of the fourth round as he and Rock finished tied at 17-under 271, finally sealed victory on the third extra hole.

"I don't know how I missed that putt on the 72nd. I just pulled it," Lowry said.

They halved the first two tries of the playoff on the par-5 18th, but Lowry made par on the third attempt as Rock missed the green with his third shot and took three more to get down.

Lowry became only the third amateur to win on the European Tour. Danny Lee of New Zealand won the Johnnie Walker Classic in February and Pablo Martin of Spain took the Russian Open in 2007.

He is the first amateur to win in his debut appearance.

As he left the green, Rory McIlroy had a brief word in his ear. "He just told me 'Don't worry. Just keep it going,"' Lowry said.

In the playoff, Rock missed a 10-footer for victory on the first hole but made a 9-footer to match Lowry's birdie at the second try.

Both missed the fairway on the next effort and were short of the green, but Lowry pitched to 20 feet and two putted. Rock cleared the green, pitched to seven feet and missed.

"I can't describe how I feel. I had an invite to play here and just wanted to make the cut. But after I shot 62 Friday, I felt I could win," Lowry said.

McIlroy, who tied 45th in a disappointing week, was delighted for his friend.

"This was awesome,"he said. "Shane's a great guy and thoroughly deserved this. To have to survive a three-hole playoff was incredible."

Lowry may decide to turn pro immediately. If he does, he can play in this week's BMW PGA Championship at Wentworth.

"I'll have to think about it overnight and talk to a few people," Lowry said.

McIlroy thought he should. "He has nothing left to do as an amateur," he said.

Rock said he was trying to chip in from off the green with his fourth shot on the last hole. "You have to. I thought I needed it to win," he said. "But I hit it too hard."

Sweden's Johan Edfors also shot 71 to take third place at 273. Marc Warren (68) and Nick Dougherty (69) were tied for fourth at 275.

European Ryder Cup captain Colin Montgomerie, in contention after three rounds, soared to a closing 80 to tie for 41st.

The son of a famous Gaelic footballer, Lowry was poised for glory when he pitched to within four feet of the final flag. But, having raised his cap to the ecstatic crowd as he walked onto the green, he was covering his face in it when he pulled the putt wide.

"I didn't think I would have a better chance than that," he said afterwards. But he did and in the pouring rain he took it to change his life forever.

"I can't believe it -- this is going to take a long time to sink in," said Lowry, who on Friday shot a 62 that equalled the lowest round ever by an amateur on the circuit.

That put him in front, and with a round to go, he shared top spot with Rock. But when he fell two behind on the 11th it looked as if he might slip quietly away.

Not so. Rock bogeyed the next and then Lowry, with fist pumps each time, birdied the 14th and 16th to go ahead.

However, the dramatic finale was set up when Rock, seeking his first win after two runner-up finishes this season, rolled in a 20-footer for birdie at the short 17th to draw level.

With Lowry's horror miss on the last they tied, but it was to prove his day after all.

"I know my life is about to change forever," he said and when asked if he would be considering turning pro he replied: "I'd be mad not to.

"I'm feeling shock more than anything. I got an invite here, it's my first tournament and I would have been happy to make the cut," he added. "But then I shot the 62 and after that I thought 'this is my week -- I can win'. And I did!"

Rock's compensation was that, because of Lowry's amateur status, he still took the first prize and with it moves into the top 10 on the money list.

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