AP

Spencer Levin watches his tee shot at the 16th hole during the second round of the Phoenix Open golf tournament.

Little-known American Spencer Levin held his nerve over the tricky closing stretch to move six shots clear after Saturday's third round of the frost-delayed Phoenix Open in Scottsdale, Arizona.

The cigarette-puffing Levin recovered from a bogey at the 15th with a birdie at the brutal par-four 17th to card a three-under-par 68 on a glorious afternoon of dazzling sunshine at the TPC Scottsdale.

In pursuit of a maiden PGA Tour victory, the 27-year-old Californian posted a 17-under total of 196 to finish six strokes in front of world number six Webb Simpson, who also carded a 68.

Long-hitting American Bubba Watson was a further shot back at 10 under, a 67 putting him level with PGA Tour rookie John Huh (69).

However no one was able to get close to the pacesetting Levin who was five strokes in front when the frost-delayed second round was completed earlier in the day.

“I hit a lot of good shots today and I didn't get into much trouble,” Levin told reporters after recording four birdies and one bogey. “I felt like I drove it good. Until 15, I hit a lot of solid shots, a lot of greens. It was stress-free.

“I hit a decent drive on 15, just barely left but if you hit it barely left there it just runs off (into the water hazard). So that was kind of a hiccup there but I made a nice putt for par on 16 and birdied 17.

“I came back from that bogey good,” added Levin, whose best PGA Tour finish was second place at last year's Mayakoba Golf Classic. “Overall it was solid. I felt I played pretty well.”

Best known for finishing joint 13th as an amateur at the 2004 US Open, Levin made a solid start to the third round, birdies at the third and fourth helping him reach the turn at 16 under, still five ahead.

He also birdied the par-five 13th, after lipping out with his eagle attempt from 22 feet, to stretch his lead to a commanding six shots.

Though Levin recorded his only bogey of the day at the par-five 15th after finding water off the tee, he birdied the driveable 17th with a deft up-and-down from a greenside bunker.

A rock-solid par at the last kept him comfortably in front of the chasing pack.

“Just go out there and try and do what I've been doing,” Levin said of his intentions for Sunday's final round.

“I know you hear guys say that all the time but if I can get out there and shoot a good score, I should be all right.”

Phil Mickelson, winner of the Phoenix Open in 1996 and 2005, carded his best round of the week, a five-birdie 67 lifting him into a tie for 10th at eight under.

Though a distant eight strokes off the pace, the American left-hander was delighted with his improved form after working with his swing coach Butch Harmon in the morning

“We had a really good session and I was able to feel much more confident,” Mickelson said. “I hit a lot of good shots, especially early on, and made some birdies.

Asked what his strategy would be in the final round, he replied: “Just shoot a good round because out here ... when you start making mistakes or hitting a bad shot, it's very hard to turn it around with water and trouble everywhere.

“And there's also an opportunity to make birdies and eagles so, if I get a hot hand and put on some pressure, you never know what might happen.” - Reuters