"It seems like every week I've had a low round," McCarron said. "I've had some chances to win and I am playing with a lot of confidence."
He missed six of seven cuts this season on the PGA Tour.
"The first part of the year stunk," McCarron said. "I was on the regular tour not making cuts. I got out here and it's been wonderful."
The 54-year-old Pate had an eagle and five birdies in his bogey-free round. He won six times on the PGA Tour.
"The way I've played this year I'm really happy it's almost over," Pate said. "I had shoulder surgery in November and wasn't really healthy until June, but I didn't have a choice."
Billy Andrade and Rod Spittle were a stroke back in the final full-field event of the season. Defending champion Fred Couples was two shots behind at 65 along with Kevin Sutherland, Paul Goydos, Jay Don Blake, Olin Browne, Scott Dunlap and Peter Senior.
The top 30 on the money list after the tournament will qualify for the season-ending Charles Schwab Cup Championship next week at Desert Mountain in Scottsdale, Arizona.
McCarron and Pate each played the three par 5s in 4 under.
"They played as easy as they could," Pate said. "Two of them were downwind and you had to take advantage of them."
Pate's eagle came on the toughest of the three, the 549-yard third.
"That can be a difficult hole," Pate said. "There is water on the left. I hit driver, hybrid to 10 feet and the putt went in."
McCarron had a chance to make eagle on two of the par 5s. On No. 15, he hit a 6-iron to 4 inches and tapped in for eagle. On No. 18, his 12-foot eagle attempt just missed on the left side.
"If I hit a good drive there, I can reach all the par 5s in two. You know, luckily today we played two of them kind of downwind a little bit so that helped," McCarron said. "Normally, I'm not hitting 6-iron in, I'm hitting probably hybrid or 3-wood in, but today with it being a little bit downwind I was able to get it out there pretty good."