Putnam had eight birdies and a bogey at windy Montreux Golf and Country Club, scoring 15 points under the format that awards eight points for albatross, five for eagle, two for birdie and zero for par, and subtracts a point for bogey and three for double-bogey or worse.
"I putted the ball really well, made a ton of putts," Putnam said. "My long game wasn't quite as sharp, but it was tough out there with the wind. It was gusty and hard to keep on balance. In this format, birdies are key, and it's almost hard to get aggressive when the wind is gusting all over the place. The last few holes you're just hitting and hoping the wind stays consistent and you don't catch any crazy gusts."
Chasing his first PGA Tour victory, the 29-year-old from Tacoma, Washington, had 38 points overall.
"A win on the PGA Tour is life changing, so I think we're all going to be hungry to get after it," Putnam said.
Saunders, Arnold Palmer's grandson, eagled the par-5 13th and 18th in a 12-point round.
"I was having a slow day, but that front nine played tough," Saunders said. "Andrew made it look easy, and it was kind of one of those moments where I had to put my blinders on and not worry about what he was doing and know that I had some birdie opportunities on that back nine. It would have been reasonable to think that I could reel off four or five birdies without much trouble, and to make it two eagles works a little better in this format."
He's also winless on the tour.
"I'm going to be thinking about it all day tomorrow," Saunders said. "I'm playing to win. I try to do that every week. If I had 15 wins, I'd still be wanting and thinking about winning all day tomorrow. Yeah, maybe it's harder when it's your first. We'll see. I've been in the position before that I am now. This isn't my first time in contention to win on Sunday, so I'm far more prepared for what I'll feel tomorrow. All I can do is play my best golf and have a good attitude out there, and if it works out, great. I'm going to be going for it on every hole, though."
He's 124th in the FedEx Cup standings, with the top 125 advancing to the playoffs and keeping their tour cards.
Chad Campbell, 138th in the FedEx standings, was third at 32 points after a 22-point day. Shane Lowry, 139th in the FedEx points, had 30 points, and Monday qualifier John Oda was another point back along with J.J. Spaun.
Campbell scored 22 points with a 10-under 62.
"In this format you really don't know how many under par you are or anything like that," Campbell said. "I was just trying to get as many as I can. I know I was quite a bit back going into today, so I needed to make a lot of points."
Campbell had a 6-under 30 on the front nine, birdieing the first three holes and three of the last four. He added birdies on Nos. 10 and 12, ran in an 18-footer for eagle and five points on the par-5 13th.
After dropping a point with a bogey on the par-4 14th, Campbell birdied the par-5 18th -- a hole where he made a double bogey in the first round and a bogey in the second.
The 44-year-old Texan won the last of his four PGA Tour titles in 2007.
Lowry eagled the 18th in an eight-point round.
"It was very hard today, very windy, really difficult to pick a club," Lowry said. "I just got off to a bad start and I just hung in there all day, and I feel like my patience was rewarded with that eagle on the last. It's this format, that's what's great about it, and that's why I'm really enjoying myself this week. You can make a move very quick. Yeah, I'm going out with a chance tomorrow now, and I'm excited."
Oda had a 13-point day.
"I've been hitting it fairly well and have been getting my putter going," Oda said. "I got a couple to go, and that kind of built some momentum and ended up making a few more."
The former UNLV star is visiting Reno for the first time.
"I stay away from up here because it's rival territory," Oda said. "I'm kidding."
Third-round leader Aaron Baddeley remained at 26 points, scoring zero points in the round.
The winner will earn a spot in the PGA Championship next week at Bellerive, if not already eligible.