Sunday at Tucson National, Wiebe carded a 6-under-par 66 to move to the top of the leaderboard at 14-under-par, while Willis fired a bogey-free 64 to climb into contention at 12-under.
Four players share third place, four shots off the lead. 1994 Tucson champion Andrew Magee (70), Kevin Sutherland (67), Glen Hnatiuk (66) and Mark Hensby (69), who is also playing in his first full season on Tour, are all tied at 10-under-par.
In all, there are four Tour rookies inside the top-10 on the Tucson leaderboard, as Q-School graduates Hunter Hass (68) and Geoff Ogilvy (68) are tied with five others for seventh place at 9-under-par.
Also in that group are two-time Masters champion Bernhard Langer (70), as well as a host of players seeking their first Tour titles - Steve Flesch (66), Harrison Frazar (66), Brandt Jobe (66) and Chris Riley (68)
Though he's played for nearly two decades, Wiebe hasn't won on the PGA Tour since the 1986 Hardee's Classic, now the John Deere Classic. He began the day two shots behind 36-hole leader Lee Porter, but carded six birdies in an eight-hole stretch to put him in position to claim his third Tour victory.
During the middle of his birdie streak, a young fan asked Wiebe for his autograph while he was sitting on the back of a cart. Inexplicably, the driver of the cart allowed the vehicle to roll backward, forcing Wiebe to grab the boy's arm and lift him onto his lap.
Shaken by the child's crying, Wiebe kept his nerves intact, birdying three of his next four holes.
Willis kept Wiebe from running away with the tournament by birdying five of his first eight holes in the third round, and eight in all. This is just Willis' fourth career start on the PGA Tour, and the first in which he's made the cut. He earned his 2001 card by tying for 11th in the Qualifying Tournament.
'There's guys that can play that nobody in this room has heard of yet that will someday pop up and we'll say, `Who is that?'' Wiebe said. 'Somebody said, `You guys have a lot in common - you really like the course.' I said, `Who is Garrett Willis?''
While Willis and Wiebe battle for the $540,000 first-place prize, Porter will be trying to salvage a decent paycheck. The overnight leader dropped into a tie for 26th place after posting a 4-over-par 76.
Due to freezing rain and snow on Friday, the event has been extended a day. You can catch final round coverage, live on The Golf Channel at 4:00pm ET.
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