The 36-hole event draws the winners of the four major tournaments but British Open winner Phil Mickelson withdrew due to a scheduling conflict. Grand Slam defending champion Padraig Harrington took his place.
Rose finished with a 4-under-par 67 while Dufner was 2-under for the first round. Scott is third at 1-under and Harrington came in at 3-over 74.
Rose was 4-under through seven holes but had three bogeys, including back-to-back at 13 and 14, and three birdies the rest of the way.
Dufner and Scott were also 4-under on the front side. But Dufner had three second-nine bogeys against one birdie and Scott a bogey and a double-bogey at the par-3 16th to slip back.
Harrington battled through an up-and-down day in which he had a double bogey -- at 16 -- four bogeys and three birdies.
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