From Brian Keogh in Houston

Rory McIlroy roared into contention for the Shell Houston Open as Padraig Harrington was driven to distraction by an errant driver.

Having had little reward for some imperious play from tee-to-green, the 19-year-old breathed a sigh of relief when he drained a slick, left-to-right, 35 footer across the 18th green to card an immaculate five-under par 67 that left him tied for 10th place on a marathon day at Redstone Golf Club.

It was no more than he deserved after letting birdie chances slip by the hole from six feet at the 15th, 15 feet at the 16th and just five and half feet after a glorious iron shot to the 17th.

Darren Clarke bogeyed two of his last three holes - the par three seventh and ninth - for a one-under par 71 that was only just good enough to share 50th place on a day of low scoring.

Americans Nicholas Thompson and Briny Baird and Australian John Senden set the pace with seven under par rounds of 65 that left them one stroke clear of six players - James Nitties, Tommy Armour, Scott Piercy, Colt Knost, DA Points and England's Paul Casey.

But it was a frustrating day for Harrington as he eventually carded a level par 72 that feature six birdies, four bogeys and a double bogey six.

Looking for a confidence boosting performance head to next week’s Masters at Augusta, the Dubliner vowed to ditch the new driver he put in his bag this week after suffering his own brand of water torture.

The triple major winner hooked tee shots into water hazards FOUR times in a roller-coaster round that left him hovering on the cut line as the field completed the first 

Heading straight to the range, Harrington groaned: “I took a new driver out and hit it in the hazard three times and on all three of them, I hit good drives.

“At the 18th it was a three wood in the water but I made three good swings with the driver at the fourth, fifth and sixth and all I can think is that the driver obviously has a hook bias in it. All three were nice shots and all three ended up in hazards.

“After the first one, you blank it out and say it is yourself. But the second and the third one convinced me it might be the driver because I made nice swings. That has to be improved.

“When I got it in play, I hit it close all day and I did very nicely. So I am pleased with some things but still need to work a little bit on my driving.”

Harrington had 11 holes of his weather-delayed first round to complete but struggled off the tee as he mixed four birdies with two bogeys and a double bogey six.

Resuming on the 17th green, he missed a six footer for birdie and then hit a three wood through the 18th fairway into the water hazard on the left and ended up making bogey.

He bounced back with a brace of birdies - hitting a pitching wedge to four feet at the first and a brilliant nine-iron to a foot at the second that left him just a shot off the lead on one-under par.

But after missing a good birdie chance at the third, he drove the ball into three water hazards in a row to drop three shots.

At the par-five fourth, he hooked into the water but saved his par after a superb bunker shot before running up a double bogey six at the fifth by driving left into the lake..

But there was more agony as he went left again at the sixth and was forced to stand in water as he blasted back to the fairway.

A birdie two at the short seventh and a two-putt birdie at the par-five eighth eased his pain and he hopes to make a run at the leaders early today.

He said: “It wasn't great but these things happen. The fact that I made a couple of birdies coming home means that at least I kept myself in there for tomorrow and if you play well for another three days you never know.”

Lee Westwood hit a 69 as world No 2 Phil Mickelson crashed to a 77 while late starter Darren Clarke was one under par through three holes with Rory McIlroy level after four holes.