Momentum swings to Zach Johnson

FORTH WORTH, Texas -- Zach Johnson tightened his tenuous grip on the Crowne Plaza Invitational at Colonial lead with a birdie on No. 15 while Jason Dufner found the drink once again and couldn't recover.

A fourth multiple-shot swing in the last seven holes now has Johnson up four shots with three holes to play. If that seems safe, re-read the part about four multiple-shot swings in this crazy final round.

Dufner found the water after his tee shot landed in a fairway bunker. Out of the water, he overshot the green and had to chip back on. Then his short putt to save a double-bogey somehow went awry and Dufner's chances of back-to-back victories might have come to an inglorious end.

Dufner is now plus-four on the day. Johnson is just minus-1 but now has the things under control as he closes in on his second Colonial championship in three years.