US Open champion Justin Rose took a two-shot lead after round one of the PGA Grand Slam in Port Royal, Bermuda.
The 33-year-old Englishman fired a four-under 67 to head US PGA champion Jason Dufner in the exhibition event for the year's four major winners.
Masters champion Adam Scott shot 70, while Ireland's Padraig Harrington, playing in place of Open winner Phil Mickelson, carded 74.
The 36-hole tournament, won last year by Harrington, ends on Wednesday.
Mickelson, who won his first Claret Jug and fifth major in all at Muirfield in July, opted not to take part in Bermuda.