Updated

Rory McIlroy and Keegan Bradley both under 67 on Tuesday in the first of two rounds at the 2011 PGA Grand Slam of Golf.

This is a two-day event at Port Royal Golf Course that features all four of the year's major winners, so this tournament's field includes Bradley, the PGA Champion; McIlroy, the U.S. Open winner; Charl Schwartzel, the Masters champion; and Darren Clarke, the British Open champ.

While a small field, the Grand Slam of Golf features some of golf's rising young stars and one of its mainstays who finally broke through. It's an interesting arrangement of players for sure, ranging from McIlroy, who may have taken over the title of 'Most Popular Golfer,' to Clarke, who searched for his first major title for so long.

All four players were first-time major champions in 2011.

At the end of 18 holes, the leaderboard was in reverse age order, with McIlroy, 22, and Bradley, 25, leading the 27-year-old Schwartzel, who shot a three-over 74, and the 43-year-old Clarke, who shot a six-over 77.

Bradley looked to run away with the event early on, but he stumbled down the stretch, and McIlroy took advantage.

Following Bradley's opening bogey, he eagled the second and birdied the third to grab the early lead at two-under. McIlroy opened with four pars before his first birdie, Clarke had three bogeys in the first four holes and Schwartzel had a birdie on No. 2 in the first few holes.

Bradley passed his lead with a birdie on the sixth and an eagle on the seventh, and he finished his front nine at six-under with a birdie on No. 9.

Midway through the round, Bradley led by four over both McIlroy and Schwartzel, while Clarke lagged behind at two-over.

Bradley cooled off over the back nine, recording only two bogeys, and Schwartzel played his back nine at five-over, including a triple-bogey at the par-three 16th.

McIlroy, meanwhile, dropped to one-under with two bogeys and a birdie on the first four holes of the back nine, but rallied with back-to-back birdies at 14 and 15. He was two back at that point and cut the deficit to one with a par on the 16th -- Bradley bogeyed -- and McIlroy's birdie on the 17th evened the score.

Bradley and McIlroy closed with pars to finish at four-under, well clear of the other two major champions.

NOTES: Last year, Ernie Els beat David Toms, Martin Kaymer and Graeme McDowell. Toms was in the field only because of an injury to British Open champ Louis Oosthuizen...Bradley is the only rookie among the four. He's won twice this year on the PGA Tour.