Hale Irwin's balky putter transformed the Burnet Senior Classic from a runaway into a dogfight.

Over the last three holes today, Irwin had a seemingly safe six-stroke lead reduced to one, clearing the way for David Graham and a host of others to challenge in Sunday's final round.

Irwin led by six strokes after 15 holes, but bogeyed two of the last three holes and settled for a 4-under-par 68 and a 36-hole score of 132. Graham, meanwhile, birdied three of the last four and his 68 left him only one shot back after two rounds over the 7,030-yard Bunker Hills Golf Club course.

"When Hale chipped in on No. 15, I thought it was over. I think everybody did," said Graham, who got a stroke back immediately when he made a 20-footer for birdie on 15.

"He just made a couple of mistakes, which was totally unexpected the way he was playing. That opened the door for some of us," Graham said.

"To everyone's pleasure -- everyone but mine, that is -- we have a horse race now," Irwin said. "I let a nice lead and good round slip away at the last stretch.

"All in all, I'm pleased with the results. I still shot 68. If I can finish it off tomorrow, I'll be pleased."

The wheels began to come off at No. 16, when Irwin's drive wandered into the rough and he put his approach to the green into a trap. He punched out to 10 feet but missed the putt. When Graham made his par, the lead was down to four.

At No. 17, Irwin's tee shot to the 180-yard hole found a trap and he failed to get down after punching out to 12 feet. Graham's 20-footer for birdie made it a two-shot swing.

Both players were on in two at the par-5 18th. Graham two-putted from 60 feet, sinking an 8-footer for birdie. Irwin, however, three-putted from 55 feet for par, allowing Graham to get within one stroke.

"I played the front nine very poorly and made two incredible par saves," Graham said. "I just kept playing. I've been in this 30-some years and I know I can't control what anyone else does. All I can do is the best I can do and hope that's good enough."

Graham saw one negative in the late reversal of fortune.

"It probably will just get Hale mad, and he'll come out here Sunday and really knuckle down."

Gil Morgan and Bob Eastwood, whose 65s were the best rounds of the day, pulled within four shots of the lead at 136, joined by Frank Conner (67), Jim Dent (70) and Jim Colbert (71).

Allen Doyle shot a 66 and was at 137, five back of Irwin.

AP