US Open champion Matt Fitzpatrick’s poor recent form continued as he suffered a heavy defeat in his opening group match in the WGC-Dell Technologies Match Play Championship.

Fitzpatrick is the top seed in group 11 at Austin Country Club, but the world number 13 had no answer to a brilliant burst of scoring from opponent JJ Spaun, who cruised to a 5&3 victory.

Spaun’s birdies on the third and fifth, combined with Fitzpatrick’s bogey on the fourth, gave the 61st-ranked American a sizeable early lead, although Fitzpatrick hit back in style with a superb approach to the par-five sixth which led to a conceded eagle.

A par was good enough to win the eighth and reduce the gap further, only for Spaun to then birdie the 11th and 12th before holing out from 107 yards for an eagle on the 13th.

Fitzpatrick, who was 14th in the Arnold Palmer Invitational but has missed the cut in three of his last four starts, needed something special to salvage anything from the contest but could not find any heroics and quickly conceded when his birdie attempt on the 15th slid by the hole.

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Spaun, who is making his debut in the event, told reporters: “I think college was the last time I played match play. It was fun though, because every shot is really intense, at least you think, because (if you) hit one bad shot, that kind of gives your competitor an opening.

“It was cool to feel more pressure from the very start of your round than normally in stroke play. I’ve been working hard on some things in my swing and it’s starting to come together. To pull it off against a guy like Matt, it’s huge for me.”

Rory McIlroyRory McIlroy (right) was also among the early starters on Wednesday (Eric Gay/AP)

Former champion Rory McIlroy was also among the early starters on Wednesday and led from start to finish to beat American Scott Stallings 3&1.

Two early birdies helped McIlroy move three up after six holes, but the world number three then bogeyed the eighth and lost the ninth to a birdie from his opponent.

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Both players did well to save par on the 10th after missing the green with their approaches before McIlroy birdied the par-three 11th to double his lead.

Stallings refused to throw in the towel and birdied the 13th and 16th, only to see McIlroy do likewise and a conceded birdie on the par-three 17th sealed victory for the four-time major winner.

Tyrrell Hatton suffered a 3&1 defeat to Ben Griffin and could be doubtful for the rest of the event after suffering pain in his right hand and arm after hitting a shot on the range during his warm-up.

The other match in group 14 saw Russell Henley threaten to pull off an amazing comeback from five down at the turn before Australia’s Lucas Herbert held on to win on the 18th.

The 64-man field is split into 16 groups of four, with only the group winners advancing to the knockout stages at the weekend.