Los Angeles - Brandt Snedeker closed with three straight birdies in a three-under par 69 on Saturday to maintain his three-shot lead at the Safeway Open, the first event of the US PGA Tour 2018-19 season.

As afternoon winds made for tough going on the Silverado Resort course in Napa, California, Snedeker came alive late.

Even for the round through 15 holes after two birdies and two bogeys, he roared home with a three-foot birdie at the par five 16th and a seven-footer at 17.

At 18, his putt from off the green left him a tap-in for his fifth birdie of the day and a 16-under total of 200.

American Kevin Tway was alone in second on 203 after a bogey-free four-under 68. Tway's back-to-back birdies at seven and eight included a hole out from the bunker at the eighth. He added birdies at 16 and 18 to edge ahead of South Korean rookie Im Sung-jae, who claimed the last of his six birdies at the 18th for a 69 that put him on 204.

He was one stroke in front of American Bill Haas, who carded a 67 for 205.

"I knew the first part of the back nine was going to be playing tough, I was just trying to survive," said Snedeker, who kept his cool as his lead dwindled.

"I wasn't driving particularly great. I was just trying to get it up around the greens and make pars and wait until I could get some downwind holes.

"I did a great job staying patient, realizing that I wasn't losing ground by making pars there."

Phil Mickelson, who started the day sharing second three strokes behind Snedeker, had his struggles, including a double-bogey six at the eighth on the way to a two-over 74.

The five-time major winner, who had been pleasantly surprised by his first two rounds after a tough 0-2 performance at the Ryder Cup in France last week, finished with three bogeys and three birdies, picking up a stroke at the 16th but unable to take advantage of the more favorable wind at 17 and 18.

He finished the day in a group sharing 15th place on eight-under par 208.

Leading scores from the third round of the US PGA Safeway Open in Napa, California, on Saturday (USA unless stated):

200 - Brandt Snedeker 66-65-69

203 - Kevin Tway 68-67-68

204 - Im Sung-jae (KOR) 66-69-69

205 - Bill Haas 70-68-67

206 - Sam Ryder 69-70-67, Aaron Baddeley (AUS) 70-67-69, Chase Wright 64-72-70, Adam Schenk 67-69-70

207 - Harold Varner 70-69-68, Nate Lashley 68-69-70, Troy Merritt 67-70-70, Alex Prugh 66-70-71, Peter Malnati 68-68-71, Ryan Moore 67-67-73

208 - Luke List 70-69-69, Bud Cauley 70-69-69, Lucas Glover 69-70-69, Fred Couples 73-65-70, Hunter Mahan 70-68-70, J.J. Spaun 72-66-70, Martin Laird (SCO) 67-70-71, Kevin Streelman 68-68-72, Phil Mickelson 65-69-74