Gabriel Hjertstedt and BellSouth Panama Championship winner Vance Veazey each shot 5-under 67s to share second place at 15-under-par 201.
Jason Dufner, who has missed the cut in nine of his 12 starts this year, fired a 6-under 66 to climb into a share of fourth place. He was joined at minus-14 by Kevin Johnson, Brent Schwarzrock, Roger Tambellini and first-round co-leader Scott Weatherly.
The third round was completed despite a one-hour, five-minute weather delay. With the potential for bad weather on Sunday, the final round will have players going off split tees in threesomes.
Matteson, who led by four strokes entering the round, got off to a nice start with birdies on two and three at Highland Springs Country Club. He settled in with five straight pars.
The Virginia Beach Open winner tripped to a bogey on the ninth to slip to minus-17. He got that stroke back with his third birdie in as many days at the par-5 11th, but trouble loomed.
Matteson, who also owns two runner-up finishes this year, three-putted his way to a double bogey at the par-4 12th. His lead slipped to one with a bogey on the 13th.
The 25-year-old fell to minus-14 and out of the lead with a bogey on No. 14. He righted the ship with a pair of pars.
Matteson got one stroke back with a birdie on the par-4 17th. He then eagled the par-5 closing hole to secure the third-round lead for the third time this year and third time in his career.
'After things didn't go our way and having some bad holes, it's always good to get some momentum going into the next day, no matter how you can get it,' said Matteson. 'We just tried to get a good finish and get some shots back.'
Matteson had a lengthy delay before he played his 18th. With water short of the green, players faced the decision to lay up or go for the green. Between that decision and penalty drops for balls going into the hazard, there were several groups on the closing hole when he got there.
'The wait was long enough that I was able to catch up with some friends,' Matteson joked. 'There were four groups waiting on the tee box, but that's understandable. When the wind died down, everybody can have a go for it when they hit a solid drive.'
Veazey opened with a birdie on the first. He came back to birdie the par-3 fourth that moved him to minus-12. The three-time winner on the Nationwide Tour parred his next six holes.
The 40-year-old ran in back-to-back birdies from the 11th. Veazey dropped in a birdie on the 15th to get to minus-15. As Matteson struggled and fell behind Veazey, Veazey birdied 16 to take a two-shot lead.
With Matteson rallying at the final two holes, Veazey stumbled to his only bogey on the par-5 18th to end two shots back.
Hjertstedt sank three birdies in a five-hole stretch from the third to move to 13-under. The Swede cruised around the turn with six consecutive pars.
The two-time winner on the PGA Tour dropped a shot on the 14th. Hjertstedt got that stroke back with a birdie on the 16th. He came right back with a birdie on 17 and made it three straight to close his round as he birdied the last to climb into a tie for second.
First-round co-leader Bill Haas carded a 2-under 70 on Saturday to end at 13-under-par 203. He was joined there by Henrico County Open winner Chad Collins, Kris Cox, Craig Lile and Steve Pleis.
Jeremy Anderson, Steven Bowditch, Rich Morris and Jerry Smith are one stroke further back at minus-12.