But Dufner needed only one hole to get even again, with an 8-foot birdie at No. 12. Johnson hit his tee shot into a fairway bunker, then his first attempt out of there hit the lip and rebounded over and behind him before a bogey.
Johnson led for the first time with a 28-foot birdie at the 382-yard second hole, where Dufner three-putted from the same distance.
Dufner regained the lead with consecutive birdies, starting with an 8-footer for his third birdie of the week at the tight par-4 fifth parallel to the Trinity River that is one of Colonial's toughest holes.
A bogey by Johnson at No. 8 had down by two. But they went to the back nine tied at 14 under, after Dufner's approach from 103 yards at the par-4 ninth hit short of the green and rolled back into the water and he made double bogey.
"There's a number of adjectives I'm calling myself right now. And lucky would be the biggest one," Johnson said. "Blessed would be another one, humbled would be another one. It's an honor to put this jacket on once. ... I'm in shock I got it twice."
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