Ben Griffin holds slim Napa lead with an amateur right behind and Scheffler closing fast

The other is far more daunting — Scottie Scheffler, the No. 1 player in all of golf, who had a double bogey Saturday and still shot an 8-under 64.

Griffin made his first bogey of the tournament on the final hole and had to settle for a 2-under 70, narrowing his lead to one shot over Koivun and two shots over Scheffler.

Griffin was at 16-under 200.

“He's proven a lot out here on tour even though he's still in college,” Griffin said of Koivun, who a week ago was leading the Americans to victory in the Walker Cup at Cypress Point.

“I know he's got a ton of game. He's right there in second place in a tour event going into Sunday, so he can play just as well as Scottie, just as well as me,” he said. “I've just got to focus on myself and stay aggressive and try to make a ton of birdies tomorrow and not have to worry about anyone.”

It should be quite a show if Saturday was any indication. The crowd was the largest since the tournament moved to Napa in 2014, even when Phil Mickelson played. This was a chance to see all but two players on the U.S. Ryder Cup team in their final appearance before going to Bethpage Black for the Sept. 26-28 matches.

Mostly they were there to see Scheffler, with the crowd four-deep on most holes with equal chants of “Scottie!” and “U-S-A!”

“If I go out and play good, consistent golf, I’m going to start moving my way up the leaderboard and that was the goal going into today,” said Scheffler, who started the round eight shots behind Griffin.

He missed only two greens and had only one big blunder, on the 14th. His tee shot drifted into soft, thick rough. He came up just short of the green and then tried to clip a wedge close to a tight pin. But it came out soft and into a bad lie in a deep bunker, he blasted out to 15 feet and took two putts for a double bogey.

Scheffler answered with three birdies on his last four holes, two of them par 5s, the other birdie a 7-iron to 6 feet on the par-3 17th.

Koivun did not get off to a great start. He had two bogeys earlier and was starting to slide down the leaderboard when he bounced back with a birdie on the par-3 eighth, and a tough shot out of a fairway bunker to 20 feet for a stress-free shot, important at the time to avoid another setback.

And then he was 5 under on the back nine, including an eagle for the second straight day on the par-5 12th, this one with a 40-foot putt.

“Didn’t have a great start, not the start I was looking for, but was able to kind of turn it around midway through the round, make some birdies, make some putts, kind of flip the script and keep myself in contention,” Koivun said.

He has a chance to become the second amateur in as many years to win on the PGA Tour, following Nick Dunlap at The American Express last year.

“I know Nick pretty well,” Koivun said. “I haven’t really talked with him about this week, but definitely might want to go watch his rerun and see what he did.”

Griffin, meanwhile, didn't make as many birdies as the opening round but still managed to keep his distance with three birdies and no mistakes until the 18th. He was playing his third shot on the par-5 18th from 127 yards in the fairway when he came up short to a front pin, bladed a chip through the green and had to get up-and-down for bogey.

Griffin won earlier this year at Colonial with Scheffler six shots behind. He also kept in the fight at Memorial in a bid to track down Scheffler. So golf's best in the mix is nothing new.

“Not too worried about what he’s going to do. I’ve just got to play better than him,” Griffin said. “And if I do that tomorrow, should be able to lift the trophy. Obviously there’s some other guys there in the mix, too, but I think everyone knows what Scottie Scheffler is capable of and I’ve just got to stay in front.”

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