Padraig Harrington leads on 5-under 66 after the first round of the 36-hole PGA Grand Slam of Golf in Bermuda - an annual exhibition event for the season's four major winners.
Harrington was called in as an alternate three days ago for Open Champion Ernie Els who is struggling with a minor ankle injury.
Masters champion Bubba Watson shot 3-under 68 and U.S. Open champion Webb Simpson a 69.
Keegan Bradley, who replaced PGA champion Rory McIlroy, rounded out the four-man field with a 72.