Graeme McDowell, pictured the second, was like an assassin on the greens against Shane Lowry. Picture Fran Caffrey / www.golffile.ieGraeme McDowell did Pádraig Harrington a massive favour when he ended Shane Lowry’s magical run and sent his pal packing in the third round of the WGC-Accenture Matchplay at Dove Mountain.

The 2010 US Open winner was too clinical on the greens for the Clara star, who missed a string of putts inside 12 feet, eventually going down 3 and 2 to allow Harrington to remain in the world’s top 50 who will tee it up in the WGC-Cadillac Championship at Doral in a fortnight.

Lowry needed to reach Sunday morning’s semi-finals to break into the top 50 and secure a place in the Miami field at Harrington’s expense.

But while his putter went cold in the crisp desert air, he flew out of Tucson proud of his wins over Rory McIlroy and Carl Pettersson and confident he can use the week as a springboard to greater things.

“There are a lot of positive to take away,” said Lowry, who’s only hope of making it to the next WGC in Miami is to come through a Monday qualifier for next week’s Honda Classic and then do well enough in the tournament to make the top 50 who qualify for Doral from Monday week’s rankings.

“I missed a couple of short putts early doors to hand Graeme a couple of holes, which you can’t do, and then he holed a couple of bombs.

“The putter was cold today. I played lovely again but against a player of Graeme’s standard. If you give him an inch, he’ll take a mile.”

Lowry knows that qualifying for Doral would now require some serious heroics. “It’s a lot of rounds away,” he said, but can still count on another PGA Tour appearance in Puerto Rico the week of the WGC. “I’ll take a lot from this week. I’ve done well and I will get some good exposure over here.

“I’ve known all along that I am good enough to compete at the highest level and I have shown myself that this week.

“It was great beating Rory because my confidence was low coming here and deep down, I wasn’t expecting to do much. But some of the golf I have played this week has given me the confidence to keep going for the rest of the year.”

Shane Lowry watches his birdie putt at the first. Fran Caffrey / www.golffile.ieMcDowell was delighted with his putting - he holed a couple of 30 footers at the seventh and ninth to go four up - and while he gave Lowry an opening by making a mess of the 15th, he was happy to win well inside the distance.

“With the possibility of another 18 holes this afternoon, I was very keen to get the match out of the way as soon as I could, especially when I was three and four up,” McDowell said.

“But Shane is a gritty competitor, very difficult to get the poker face on and really knuckle down and play Shane, being a good friend like he is.  

“When he hit that pin with the flop shot on 13, I was licking my chops there thinking I had a chance to go five up with five to play, and all of a sudden I found myself down 16 and really not wanting to go down much past that.”

McDowell got off to a slow start but still walked off the fourth green one up, when he could have been a couple down.

Lowry won the par-five second but then lost five of the next seven holes - two of them to pars - to find himself four down at the turn and all but out of the event.

Under pressure to avoid mistakes, it was his putter that let him down as McDowell showed little mercy on the greens.

After being forced to chip and putt for a half in par at the first, a poor lay up into a fairway bunker cost McDowell the par-five second, where Lowry hit an average chip to 10 feet and holed the putt.

But it turned out to be the last significance putt inside 12 feet that the Offaly star would hole until he knocked home a six footer for a half at the 10th to remain four down.

Shane Lowry gained invaluable experience in Tucson. Fran Caffrey / www.golffile.ieAt the par-three third, the 25-year old pushed his tee shot into the bunker right of the green and missed an eight footer for a half after McDowell had failed with a 10 footer for birdie.

At the fourth, he took driver off the tee and it proved to be a fatal course management mistake as he drove through the fairway into a waste area and could only chip out, eventually missing an eight footer for a half after a tentative chip.

Twelve feet away at the fifth with McDowell just eight feet from the hole, Lowry missed again and the Ulsterman pounced to go two up.

He looked odds on to win back a hole at the 165-yard sixth when McDowell missed the green and he rifled a superb approach to just six feet.

But he missed the putt and McDowell got up and down for the half, clinically rapping home a tricky four footer.

The Ulsterman then turned the screw with some superb putting and short game play to birdie the next three holes and take a commanding four up lead at the turn.

At the seventh, the 2010 US Open champion’s slippery 30 footer toppled in on the last roll for birdie and almost inevitably Lowry missed from 12 feet for the half.

Even when he was forced to lay up from the rough at the par-five eighth, McDowell proved unstoppable.

With Lowry just off the green in two, 10 yards from the pin, McDowell hit a 106-yard wedge to five feet and holed the putt for a half in birdies after Lowry’s attempted chip-in checked too much and came up short.

At the ninth, both were 30 feet away and after tossing a tee to decide who was away, McDowell cruelly holed his putt, clenching his fist as he watched it crown a ridge and drop after a sharp right turn at the hole.

Lowry’s effort never had a chance after that and he had to hole a six footer for par at the 10th jsut to remain four down after bunkering his second.

It was only the second putt inside 12 feet that he made from seven attempts in the first 10 holes.

He needed something to happen fast but halved the 11th and 12th in par and then hit the pin with a spectacular flop shot at the par-five 13th.

McDowell had a putt to win the hole and five up with five to go but a four hole deficit was still too much for Lowry.

After halves in birdie threes at the 14th, McDowell lost the 15th to Lowry’s par four after driving left into the desert. But he closed out the match at the next , holing a six footer for par after Lowry had missed an 18 footer that would have extended the match for another hole.

McDowell went on to face Australia’s Jason Day who beat Masters champion Bubba Watson 4 and 3 with the winner of their clash set to face Robert Garrigus or Matt Kuchar, who defeated Fredrik Jacobson (3 and 1) and Nicolas Colsaerts (4 and 3) respectively.

In the other half of the draw, Webb Simpson beat Gonzalo Fernandez Castaño one up to meet defending champion Hunter Mahan, who had a 5 and 4 win over Martin Kaymer

Steve Stricker holed a 30 footer on the last to beat Scott Piercy 1 up, carding a 64 to Piercy’s 65,matchplay specialist Ian Poulter, who eased to a 5  and 3 win over South Africa’s Tim Clark.