Rory McIlroy has vowed to rid himself of a "Dufnering" mode and display greater aggression over the final two rounds of the Shell Houston Open.

It was as though everyone in America's fourth largest city was willing McIlroy on to birdie at least one of his closing seven holes and he did so, at his penultimate hole, in carding a 70 for a one-under- par tally.

In the Masters scheme of things, there could not have been a more important 18 holes of golf, with the last thing McIlroy needing before the season's first major a weekend off in suburban Humble after missing the cut.

"Dufnering" is a craze that's swept the Houston event and originates from picture taken of American Jason Dufner sitting on a floor and looking totally "out of it", but then little did golf's most laidback player expect the picture to start a craze.

"It's the best thing I ever saw, and I've never had so much entertainment going through all the 'Dufnering' YouTube clips last night in my hotel room," said McIlroy.

But, on a more serious note, McIlroy confessed he con-tinues to be too tentative and holding back on his shots but now that he is assured of two more Houston Open rounds, he needs get with the Texas catchphrase – "Everything is big in Texas".

"I've found myself holding back a bit and that's something I wasn't doing at Doral, and maybe it's because I haven't played a tournament in a couple of weeks and I'm just trying to ease my way into it a bit more," said McIlroy. "But it's just good to have these two rounds of the weekend and sort of get myself out of that habit."

McIlroy began his round from the 10th hole at one over and finally managed to make his way into the red with birdies of four feet at the 15th and then, after hitting an 8-iron tee shot at the next, the world No. 2 holed an 18ft putt.

"I noticed that I was T77 when I walked on to the seventh green [his 16th] and I knew I probably needed a birdie coming in and which I was able to do," said McIlroy.

He achieved that goal at the next, the par-5 eighth hole and hitting a 280-yard fairway wood just short left of the green from where he knocked the ball up to four feet to putt for birdie.

While McIlroy is guaranteed two more rounds, Scotland's Martin Laird is heading for the weekend off.

Laird commenced his round at three over but nose-dived after flying through the green by some 40-yards at the par-4, fifth hole and then, when on the green, three-putting from seven feet to be five over and out of contention.