Spencer Levin didn't have the kind of big performance he put together during his first two days at the Phoenix Open, but avoided big mistakes Saturday and emerged with a commanding lead.

Levin shot a three-under 68 during his third round at the TPC Scottsdale to move to 17-under-par 196. He had posted 65 and 63 for his first two rounds, and had only one bogey Saturday to protect his lead.

The 27-year-old is now on track for his first PGA Tour victory, six shots ahead of Webb Simpson, who made a run on the back nine. He threatened to get within three shots at one point, but just missed a long birdie putt at 16. An ill-timed bogey at No. 17 dropped Simpson further back, and he finished with a 68 to move to 11-under.

Bubba Watson (67) and John Huh (69) are tied for third, one shot behind Simpson.

Phil Mickelson carded a four-under 67 in Saturday's third round and is tied for 10th at minus-eight.

Harrison Frazar started the day within three shots of Levin, still having to play the final three holes of his second round -- frost delays on Thursday and Friday set the tournament back.

However, Frazar played his 21 holes in four-over par to slide down a leaderboard. He posted a 73 for his third round and sits in a tie for 12th at seven-under.

Saturday's round didn't feature much drama until the middle of the back nine.

Simpson and Levin, playing a group apart, both birdied the 13th and were separated by six shots when Simpson teed off at the par-five 15th.

Simpson moved down the fairway before placing his third shot within four feet of the hole, and made the birdie putt to get to 12-under.

Levin, on the other hand, drove his tee shot into the water. He still managed to create a chance to save par, but missed the 19-footer and tapped in for bogey, falling back to 16-under.

Simpson was up ahead at the par-three 16th, surrounded by raucous fans packing the grandstands, with a chance to draw within three strokes. He faced a 50- foot putt for birdie and nearly ran it home, but ended up with a short putt for par.

After Levin also parred No. 16, the momentum swung back in his favor.

Simpson's tee shot at the par-four 17th was just to the right of the green, but his second rolled past the pin, off the edge and into the water. Following his penalty stroke, Simpson made a tough six-foot putt just to limit his losses to a bogey.

Levin looked like he might follow with a bogey when he drove into a bunker to the back right edge of the green. But he blasted within three feet of the hole and sank the birdie putt to get to 17-under.

"Hit a decent drive on 15, just barely left, and if you get it barely left there, it just runs off," Levin said during a television interview. "That was kind of a hiccup there, but made a nice putt for par on 16 and birdied 17. Came back from that bogey good."

In contrast to the first two rounds -- when he had 13 birdies and one eagle -- Levin posted just four birdies Saturday. He played a mistake-free front nine, sinking a four-foot birdie putt at the third and draining a 16-footer at the fourth.

Simpson, a two-time winner last year, had mixed results during his front nine -- bogeys at the first and seventh, with three birdies in between. He made the turn at nine-under, then birdied the 11th to move another shot closer to Levin.

NOTES: Levin had gone 49 consecutive holes without a bogey before the 15th...He had never held a piece of the 54-hole lead in a PGA Tour event before Saturday...Jason Dufner, who lost to Mark Wilson in a playoff at last year's Phoenix Open, is in a group of five tied for fifth at minus-nine. Dufner shot a 68 Saturday, and is joined by Chris Stroud (66), Greg Chalmers (67), Ben Crane (68) and Kyle Stanley (69)...Many players wore green Saturday in support of the tournament's "Green Out," a promotion supporting the environmental efforts of the Phoenix Open's title sponsor, Waste Management...Saturday's attendance was 173,210, a new tournament record...Saturday would have been the 100th birthday of PGA legend Byron Nelson.