ALOHA, Ore. -- When Tom Watson faltered, Jim Ahern took advantage.
Ahern birdied three of the final four holes for a 4-under 68 Saturday to take a one-stroke lead after the third round of Jeld-Wen Tradition, the final major this season on the Champions Tour.
Ahern was at 14-under 202 after 54 holes heading into Sunday's final round at the Reserve Vineyards and Golf Club west of Portland.
"I played really a solid round of golf today," he said. "Tee to green, I was really right on."
Hale Irwin, the winningest senior with 37 tour victories, shot a 2-under 70 despite trouble with back spasms and was alone at 12-under 204.
"I haven't had a chance to really look at the leaderboard, but boy, there's a lot of guys there right behind me," Ahern said.
It was a roller-coaster round for Watson, the second-round leader by four strokes.
"I guess it was the law of averages. Yesterday was a superb day. Today was a very ugly day, as far as my standards," Watson said.
Bogey-free for the first two days of the tournament, Watson dropped his first shot on the par-3 No. 2 hole Saturday -- then bogeyed the par-4 third hole to narrow the field. Ahern birdied the No. 3 hole to come within a stroke.
"He's a very focused player," Watson said about Ahern, who played in his group. "He hit quite a few beautiful shots."
Irwin was also in the threesome.
"I kind of talked to myself before I went out to play and said, 'Don't get caught up in these two Hall of Famers that you're out there with today. Just pay attention to your game, one shot at a time," Ahern said.
But Watson had back-to-back birdies on the fifth and sixth holes to climb back to 14 under.
Bogeys on Nos. 12 and No. 13, both par-4s, dropped Watson two strokes and allowed Irwin and Kite to pull even. From there, it was a tug-of-war among the leaders for dominance.
Hatalsky said it was anyone's guess who might emerge with the win Sunday.
"I don't know if it's going to have to be a real good number; it depends on the conditions," he said.
Watson shot a 62 Friday to set a Tradition record with a second-round 14-under 130. He broke Phil Rodgers' start in 1991 and Gil Morgan's 1997 score at Desert Mountain in Scottsdale, Ariz.
This is the first time the tournament has been played in Oregon after 14 years in Arizona.
Defending champion Jim Thorpe had a 4-under 68 and was three strokes off the lead at 11-under 205.
Ahern has been pushing himself to finish in the top 30 on the Champions Tour money list this year after winning the Music City Championship in June, only the third title of his pro career. But he had slipped from 24th to 35th over the past two months.
"I've never led a major -- so kind of uncharted waters for me," he said.
Watson, meanwhile, has five Champions Tour victories to go with his 39 PGA Tour wins. He has six top-five finishes on the senior tour this year despite playing a limited schedule.
The galleries greeted Watson and caddie Bruce Edwards with warm applause. Earlier this year, Edwards was diagnosed with ALS, also known as Lou Gehrig's disease.
Jack Nicklaus finished Saturday with a 4-under 68 to stay in contention at 9-under 207. It was the ninth and final tour event this season for Nicklaus, who has won the Tradition four times.