Rory McIlroy mounted a desperate late rally before falling to a surprise 2 and 1 defeat to American Peter Uihlein on the opening day of the WGC-Dell Technologies Match Play in Texas.

Less than 72 hours after blasting five birdies in his last six holes to win for the first time in 18 months at the Arnold Palmer Invitational, the world number seven did it again yesterday but only when he was already five down.

Having said last week that the Match Play was good preparation for the cut and thrust of the Masters as "you're reacting to what's going on in front of you." he admitted he was “flat” early in his match against the 2010 US Amateur champion and rallied too late.

"I made him earn it at least, I made the scoreline a little more respectable," said McIlroy, who faces Jhonattan Vegas today after the Venezuelan birdie the 18th to halve the other match in Group Six with left-hander Brian Harman.

Knowing he must win to keep alive his chances of advancing to the knock out stages on Saturday, McIlroy said: "I just came away a little flat. I didn't really necessarily play badly. He played pretty well. It was a few under through nine and got down early and he didn't make a bogey all day."

He didn’t get fired up until he was dormie five and a heavy defeat looked inevitable before he made a 36 footer for a birdie from the fringe of the 14th and then birdied the 15th and 16th from close range to cut the gap to two holes.

He needed a 16 footer for a two at the 17th to take Uihlein to the last but he missed and the American cleaned up from three feet for a valuable win.

"It was hard to claw my way back," McIlroy said. "It was gusty out there, the conditions were a little tricky. As I said, I made a run at him at the end, but it was a little too late."

Under the round-robin system, the 16 group winners advance to the knockout stages and with Vegas halving with Harman, McIlroy knows his fate is not in his hands.

"Obviously it's out of my control now," he added. "So I've just got to win my next two matches and hopefully the draw works in my favour."

While he was deadly with the putter at Bay Hill, McIlroy gave himself little chance of recovering from a slow start.

He missed a seven-footer for a half in birdies at the second, bogeyed the par-three fourth and then failed to get up and down from 25 yards for a half in birdies at the driveable fifth.

Uihlein hit a wedge stone dead at the ninth to turn four up before extending his lead to five holes when McIlroy bogeyed the 10th.

The Northern Ireland star birdied the par-five 12th and the driveable 13th but Uihlein matched him each time to be dormie five.

McIlroy needed to win the next five holes but while he won the 14th, 15th and 16th, there was no to be no miracle.

“It could have gone two ways,” Uihlein said. “Either he was going to come out and blitz it and I was going to be five down early or he was going to come out a hair flat.

“It’s always difficult to come out after a big week. So I was lucky I took advantage of it early and I am glad to have it end this way for sure.”

McIlroy wasn’t the only surprise loser on the first day as world number one and defending champion Dustin Johnson fell 3 and 1 to Austria's Bernd Wiesberger and Phil Mickelson lost 3 and 2 to Charles Howell III.

European number one Tommy Fleetwood fell 3 and 2 to 2010 Accenture Match Play champion Ian Poulter, who needs to reach the quarter-finals to qualify for the Masters.

Struggling with his putting recently, Poulter said: "Rory turned it around last week. His putting stats were pretty incredible.

"So again, it comes down to the wand. If I can warm that thing up and play well for the next three days, four days, five, I'll have a chance to obviously make it." 

Two-time winner Jason Day opened his account with a 4 and 2 win over James Hahn as Open champion Jordan Spieth beat Charl Schwartzel 2 and 1.

Paul Casey won the 18th to defeat Russell Henley 1 up. Those respective victories took Poulter and Casey’s total of career victories at the WGC – Dell Technologies Match Play to 24, which tied them with David Toms as the second most prolific winners in the event’s history. Tiger Woods holds the record number of wins at 33.

New father Sergio Garcia won a hard-fought match against the current Race to Dubai Number One Shubhanker Sharma on the 18th green. There were also first day wins for Kiradech Aphibarnrat, Rafa Cabrera Bello, Ross Fisher, Tyrell Hatton, Francesco Molinari and Alex Noren.

Bernd Wiesberger

“I thought it was the easiest game I could have. I'm the underdog playing with the defending champion, so it was a case of just try to go out there and see what happens. We both didn't have a great day, obviously, as you can see on the card. He gave away a couple of holes quite unexpectedly. You've still got to make the par when your opponent makes the bogey. I didn't hit it as great. The golf course was tough and the wind was gusting. Just happy to get through the match.”

Peter Uihlein

“I was solid most of the day. I really snuck one out on the 1st to tie that hole, was pretty big from a momentum standpoint. After that, I hit every green pretty much up to 16. And I just kept putting pressure on him all day. And I felt like, especially on the front, I was always having a chance to win the hole with a putt.

“I think when you're able to do that in match play, you kind of control your fate or control how the match is going to go. You always feel like a guy like that -- really any player seems like out there, they're eventually going to make a run. You're going to trade blows little bit. And he landed some at the end. And I was able to kind of hold him off, which was nice.”

Ian Poulter

"Winning match play is always really pleasing. Tommy is a great player. I don't think either of us really holed any putts. I think I probably played just a little better than he did and obviously got it done.

“The simplicity of match play is win your match. It sounds really easy and it's not. So level of focus, level of concentration this week. Be super aggressive, try not to hand too many holes away. It's a tricky golf course this week. It's easy to get out of position and it's easy to hand holes to your guy with not really doing too much wrong. I'm happy with the win. A little practice with this putter, it needs to kick in, needs to warm up a little bit.”

Paul Casey

“You never need to be up until the end. It was a very close match. It felt a bit flat out there. Nobody threw anything to the opponent. I feel a bit guilty to walk away with that one. But then again, I don’t care. It is what it is. Very, very happy to get the win.”

Round one results

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