SILVIS, Ill. — Calm skies and a near-perfect course gave every golfer at the John Deere Classic the chance to shoot a really low number on Saturday.

Daniel Summerhays went lower than everyone else, seizing firm control heading into Sunday's final round.

Summerhays shot a 9-under 62 for a two-stroke lead following third-round play. Summerhays, whose previous best finish on the PGA Tour was a tie for fourth, enters the final round at 19-under 194 and in position for his first career win.

He notched 10 birdies while matching the lowest third-round score in tournament history.

"I think when I'm playing well the mentality is make as many birdies as you can," Summerhays said. "I'm really looking forward to (Sunday). I'm playing really well."

Canadian David Hearn (64) is second at 17 under. Defending champion Zach Johnson held a share of the lead after each of the first two rounds, but he's now alone in third after shooting a 67.

J.J. Henry and Jerry Kelly are tied for fourth at 15 under, while Nicholas Thompson leads three golfers at 14 under.

Summerhays had missed three straight cuts — failing to shoot a round under 70 in those events — before finishing ninth last week at the Greenbrier Classic.

He's been hot all weekend at Deere Run, though, and Saturday marked the lowest round of his career.

Summerhays blew a 2-shot lead during the final round of the Mayakoba Classic in Mexico last year and finished fifth, but he insists that he'll take an easygoing approach into Sunday.

"I know there's going to be obstacles and challenges, as there always are. There are always things that stand in your way. But I'm just excited to see what those are and deal with them," Summerhays said.

Hearn finished with three birdies in four holes to pull within two shots of Summerhays. After matching 66s, Hearn went two strokes lower to give himself a chance on Sunday.

Johnson had been remarkably consistent over his last six rounds at Deere Run, but for the first time in a long time, Johnson found himself battling just to hang close to the leaders. He eagled No. 2 with a 60-foot putt to grab the lead outright but a bogey at the par-4 6th was his first here in 62 holes, and he picked up another one five holes later.

Still, Johnson likes his chances heading into the finale.

"I certainly think there were a lot more positives out there than negatives," Johnson said. "My putter has been great. Even the ones I've missed have been great."

No amateur has won on the PGA Tour in 22 years but for about 15 minutes, unheralded Stanford amateur Patrick Rodgers was alone atop the leaderboard.

Rodgers was 7 under through 12 holes — a stretch capped by a winding 57-foot birdie that put him a shot clear of the field — and enters the finale at 12 under.

"Kind of got a mental hurdle off my back making my first cut in a professional event, so (Saturday) was pressure free. It was good. I could just go out there and make a ton of birdies," said Rodgers, a two-time All-American at Stanford.

Three-time tournament winner Steve Stricker (69) is eight shots back of Summerhays. He'll need a tremendous final round and some serious help to claim his fourth title in five years.

But the conditions are supposed to be great again on Sunday, giving Stricker and a lot of other golfers at least some hope of catching Summerhays.

"I'll just have to come out and do the best that I can, and like I say, put up a low number. And they're out here. The low number is out here," Stricker said.