Jason Dufner holds onto 1-shot lead

FORT WORTH, Texas -- Jason Dufner had a three-shot lead with five holes to go, but he was unable to pad it and instead saw Zach Johnson, the 2010 champ and course record-holder, close the gap to one stroke at the end of Saturday's third round at Colonial.

Johnson had an opportunity to tie on the 18th, but his birdie putt rode a rail on the left side of the cup and came to a halt inches away.

The Crowne Plaza Invitational at Colonial is a two-horse race to be decided during Sunday's final round between Dufner (15-under), last week's Byron Nelson champ who is trying to become the first player since Ben Hogan in 1946 to win the DFW double in the same season, and Johnson (14-under).

Johnson fired a 31 on the front nine and twice tied tied Dufner in the first 10 holes. But Dufner quickly birdied to regain the lead each time and then used three consecutive birdies to start the back nine to get to 16-under and take a three-stroke lead.

But Dufner couldn't capitalize on No. 14 after Johnson bogeyed to fall to 12-under. Dufner, with a chance to take a four-stroke lead, missed a short putt and settled for the bogey. He then bogeyed No. 16 to make it a one-stroke tournament as Johnson birdied No. 13 and No. 17.

It will take a heck of a day for anyone else to make a run at the plaid jacket. Tom Gillis is eight shots back of Dufner at 7-under, Bo Van Pelt is at 6-under and John Huh and Ryan Palmer are 5-under after another very warm, humid and windy day at Colonial.