SOUTHAMPTON, Bermuda (AFP) - United States Open champion Justin Rose fired a four-under par 67 on Tuesday to take a two-stroke lead after the opening round of the four-man Grand Slam of Golf.

PGA Champion Jason Dufner carded a two-under 69, Masters winner Adam Scott fired a one-under 60 and defending champion Padraig Harrington stumbled to a three-over 74.

Harrington replaced British Open champion Phil Mickelson in the event designed to pit the year's four major champions against each other.

Rose, Dufner and Scott, all first-time major champions in 2013, were tied for the lead at three-under on the tee at the par-three 16th.

Scott's tee shot landed in a greenside bunker and the Australian ended up with a double bogey.

"It was impossible to get it near the hole," Scott said of his sand shot.

"I was trying to hit it 50 feet long up near Justin's ball, but misjudged it a little bit and it came out so soft." Dufner left his tee shot short en route to a bogey, and Rose seized the outright lead with a par.

England's Rose birdied 17 to stretch his lead.

"I felt like I didn't really play my best today, but I kept the ball out of some really bad spots out there on the golf course," Rose said. "I felt like I putted really well today." The tournament concludes on Wednesday with another 18 holes at Port Royal Golf course.