McIlroy plays through pain barrier after smashing wrist

Ulsterman finishes round on even par but scan could determine whether he continues

Rory McIlroy holds his wrist in pain after hitting a drive off the fifth tee (AP)

Rory McIlroy was undergoing an MRI scan at an Atlanta hospital last night to see whether he could continue in this USPGA Championship. Even in the context of the Ulsterman's roller-coaster career this could be considered a day of mind-boggling drama.

Certainly the 22-year-old showed remarkable courage and extraordinary talent to post a level par 70, despite jarring his wrist on the third hole. But would all the grimacing, all the shots completed with one arm, be worth it? He really is the new Tiger Woods. Wherever he goes, stories follow.

All in all it was promising to be a nervous evening for the 22-year-old. If he is able to resume his challenge at 8.35am today, he will find himself seven behind the leader, Steve Stricker. The American so almost became the first player in the history of the majors to post a 62. But he missed a 10-footer on the last and had to be content with joining the other players who have recorded 63s. On any other day, that would fill the headlines. But not this Thursday.

McIlroy even managed to knock Tiger Woods's 77 – his worst opening round ever in a major – out of the spotlight. It was the crack heard around the world. When McIlroy smashed a seven-iron into the root of a tree his USPGA, if not his season, flashed before him. The pre-tournament favourite immediately knew he was in trouble. Indeed, while the ball ricochet among the trees, his wrist jarred so badly the club flew 10 yards.

Initially, he was forced to press a cold water bottle against his right arm, before an official brought an ice pack. McIlroy had somehow managed only to bogey the third and was in the process of parring the fourth when Jeff Hengra, a PGA Tour physiotherapist, appeared to examine the injury. After a long consultation McIlroy continued but his anguish was obvious. Darren Clarke, his playing partner, offered advice. "Don't do anything stupid for the sake of playing," the Open champion told his fellow countryman, who for so long looked up to him as a mentor.

The angst was shared by many of his colleagues, not least Luke Donald. "Just walked by a TV and saw Rory hurt his wrist," tweeted Donald. "Made me feel sick. Bad memories."

The drive on the fifth was the critical moment. He hit the fairway but again his hand came off the club and again he winced. The mind went back to the 2008 US Open at Torrey Pines when after almost every shot Woods was in agony. Of course, Woods famously proceeded to win "on one leg". Could McIlroy become the "one-armed" champion?

The outrageous fantasy became slightly more plausible when he produced another great bunker shot to birdie the par-five fifth and then holed a long putt on the sixth. He was still in distress and in red figures at one-under par. By now his own physiotherapist, Cornel Driessen, was accompanying him and was giving treatment on every hole. He had assured McIlroy that by continuing he would not be risking serious injury. Driessen applied heavy strapping on the ninth, and then again on the 10th, and was following in close pursuit. On the 12th he was seen next to McIlroy, whose ball was buried among the pine needles. It appeared he said something to McIlroy, who laughed, before chipping out. It was a moment reported to the rules men.

McIlroy was oblivious to that particular rumpus, stoked up by eagle-eyed television viewers. He had quite enough on his plate as he continued to fight the pain and defy the odds, holing a monster for a par on the ninth. "He's playing remarkable golf," said Colin Montgomerie. "Let's hope he can give himself a chance."

And all the while another question was burning. Should McIlroy should have taken on the shot on the third? It was obvious he would hit the root, but McIlroy must have believed he could power through it. The root won. Ian Poulter tweeted his concern. "Rory shot on three was risky, hope his wrist is okay," wrote the Englishman after his first-round 74. "It was either tough or dumb – or both," said the American pro Arron Oberholser.

The spotlight would inevitably fall once again on the role of his caddie, JP Fitzgerald; but McIlroy is his own man. His belligerence was borne out in a back nine which saw him perform a few mini miracles. On the 13th a bunker shot under the lip was flicked up to a few feet, on the 14th a fairway bunker shot was coaxed on to the green. Then came the arduous run-in. McIlroy played an audacious approach to a few feet at the 16th – his right hand again coming off the club – but there were bogeys at the 15th and 17th.

Still in the agony of four hours earlier he would have bitten someone's hand off for a 70.

What a year it has been for McIlroy in the majors. The final-round 80 he shot when leading The Masters, the record-breaking seven-stroke triumph at the US Open, all the attention at the Open as he filled the void left by the absence Tiger Woods. And now this "will he or won't he" saga. Plus the rules hullabaloo. Extraordinary. "I feel sorry for Stricker," said Montgomerie. "All this furore takes the focus away from his brilliant round."

Indeed, it could have been historic. Following seven birdies and no bogeys he came to the last needing a three to break the magic 63 barrier. Every other 10-footer had dropped but this stayed above ground. Nerves? "I didn't even think about it," admitted the 44-year-old, after taking a two-shot lead over his compatriot Jerry Kelly. "It was only after I missed it that my caddie said 'you know that was for the lowest round in major history'. I was like 'oh shoot'."

Oh shoot – it summed up the day. In all the commotion it was easy to forget the other players. There was the extraordinary 18-year-old Matteo Manassero on two-under, the same mark as Yorkshire's Simon Dyson after 16 holes and there was the world No 2, Lee Westwood, struggling on two-over with one to play. But stealing all the attention was McIlroy. There can now be no doubt this compelling young man is Tiger's heir.

Up and down: How they fared on day one in Atlanta

Nightmare of the day

Japanese phenomenon Ryo Ishikawa pledged to give all his earnings in 2011 to a Japanese relief fund helping victims of March's earthquake – but he sadly won't be taking home a lot from Atlanta. The world No 40 carded a horrific 85 to prop up the field on 15 over par, including five double-bogeys and a triple-bogey.

Outfit of the day

While not quite measuring up to the eye-wateringly bright orange shirt and psychedelic trousers he sported in practice, John Daly again wowed the crowds. The chain-smoking 45-year-old, winner of the event 20 years ago, continued his 1960s theme with a pair of hideous flower-power trousers.

Shot of the day

Tiger Woods came into the tournament predicting a first major in three years but this was his worst opening round in one of the big four events. He rolled back the years on the 12th though, recovering from a terrible tee effort to strike an outstanding bunker shot and move to within a couple of feet of the par-five hole, rescuing birdie.