Caron posted a 4-under 67, while McRoy fired a 6-under 65 in round three. The duo is knotted at 11-under-par 202 at Empire Lakes Golf Club.
Jeff Klauk (65) and Tom Carter (66) share third place at minus-10.
Caron collected his first birdie at the fifth, then parred his next six holes. At the 12th, Caron rolled in a 10-footer for birdie to reach 9 under par for the championship.
He dropped his only shot to par at the par-3 14th, but made up the lost stroke with a chip-in birdie from short of the putting surface at the par-4 16th.
Caron was back to 9 under par until he got to the par-5 closing hole. He hit a pair of 3-woods to get to 30 feet, then drained the long eagle try to match McRoy at the top of the leaderboard.
Caron will be in search of his first Nationwide Tour victory come Sunday.
'I'm trying to stick to my game plan,' said Caron. 'I've been working hard on my game and it's finally coming through this week. I'm trying to be patient and that's what I'm going to try and do tomorrow.'
McRoy tallied four birdies on his front side and added No. 5 at the 10th. He birdied the par-3 17th to get his piece of first place.
The 2002 B.C. Open winner on the PGA Tour will be in search of his third win on the Nationwide, but his first since 2000, when he captured the Dakota Dunes Open and the Tour Championship.
David Branshaw (66), Troy Matteson (67) and Jaxon Brigman (68) are tied for fifth place at 9-under-par 204.
Overnight co-leader Mathew Goggin only managed an even-par 71 on Saturday and is tied for eighth place with Michael Clark II (68) and John Mallinger (69). The trio is knotted at minus-8.
The other second-round co-leader, Tom Scherrer, struggled in the third round. He shot a 2-over 73 and is part of a group tied for 16th place at 6-under- par 207.