Dufner had consecutive bogeys at Nos. 2 and 3, but quickly responded with consecutive birdies on the following two holes.
After a bogey at No. 11 following a bad tee shot, Dufner got back to 10 under with his birdie at the par-5 16th, when he blasted out of a greenside bunker to 6 feet.
The last of Mickelson's four birdies in a row came when he holed a 30-footer at the 461-yard eighth hole. That got the 10th-ranked player to 6 under at about the same time Dufner and Henry were finishing at No. 1, both at 8 under.
Mickelson was 8 under after a birdie at the par-5 16th, but his 3 1/2-foot par putt at the following par 3 circled the cup and rolled back toward him for his first bogey of the day.
"I was certainly disappointed with not getting that birdie," he said. "If I could get 17 or 18, get to 9 of 10 (under), you just never know."
Divots: Vijay Singh, a 34-time PGA Tour winner whose last victory was in 2008, was within two strokes of the lead after his third-round 66. He started Sunday with three consecutive bogeys, on way to a 71 and part of a ninth-place tie at 275. ... Bradley the nephew of LPGA great Pat Bradley who got his first PGA Tour victory at last year's Nelson, had a triple-bogey 7 at the 232-yard 11th hole for the second day in a row. He shot 72 for a 278 total.
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