Most guys goofed about in the clubhouse or listened to their iPods during yesterday's two-hour storm delay at the Nedbank Challenge; unlike Rory McIlroy, who had to be placed on an intravenous drip by the tournament doctor.

McIlroy had been complaining of flu-like symptoms since his arrival in Sun City from Hong Kong last Monday and plainly was still under the weather as he posted a one-over par 73 in the opening round of this week's lucrative 12-man shootout.

This left the exhausted Holywood youngster in a tie for 10th place with England's Ross Fisher and American Nick Watney, five off the pace set by Robert Allenby, who skipped his national Open this week to play in the $4.35million South African extravaganza.

It remains to be seen if McIlroy can survive all 72 holes of his sixth tournament in seven weeks but judging by the bravery he showed yesterday, the 20-year-old will not give up without a fight.

From the off, McIlroy clearly was out of sorts. After untidy bogeys on the first and third holes, the latter by way of an annoying three-putt, it became patently clear how grim the Ulster prodigy was feeling when he failed even to raise a smile after an unlikely birdie at the par three fourth.

The past few weeks have been mentally draining for McIlroy. Especially crushing was his Dubai World Championship defeat at the hands of Lee Westwood the weekend before last and he appeared to run out of steam at last Sunday's climax to the golf World Cup at Mission Hills.

After a phenomenal year, in which McIlroy registered his maiden Tour victory in Dubai last February and had a dozen top-five finishes as he soared to No 10 in the world rankings, the kid plainly has hit the wall in his final event of the season.

Still he battled on yesterday, interspersing lacklustre shots with occasional flashes of brilliance. Another birdie at five was followed by bogeys at seven and nine before McIlroy picked up a shot at 10, just before the siren, signalling the imminent arrival of an electrical storm, brought play shuddering to a halt.

He took the opportunity to visit the doctor and, after an hour on an IV drip, McIlroy rejoined his playing companion, Masters Champion Angel Cabrera, on the golf course for the resumption of play.

Undeterred by another couple of dropped shots at 13 and 16, McIlroy came up with a real grandstand finish, hitting a superlative wedge in to a couple of feet at 17 and then sinking a 25 foot putt at 18 for two phenomenal back-to-back birdies.

Even John Wayne would have struggled to match true grit like this.