Niagara Gazette — Shin, from Hamilton, Ont., led most of the day at 13-under, but dropped a shot on 17 that opened the door for Pendrith.
"I got some help with the trees on 17," he said. "I hit a bad first shot and ended with a good bogey there. I was happy with that."
Both Shin and Pendrith said playing together in the final pairing could be advantageous. The two also share a home course at the Summit Golf and Country Club in Richmond Hill, Ont., and they said playing together could help their games.
"I'm very excited for tomorrow," Shin said. "We're going to have fun.
"He's a real nice guy. ... We play a lot together, so it will feel like we're just practicing."
Joining the duo in the final pairing will be Day Two leader Tyler Dunlap.
The Trophy Club, Texas product shot an even-par 70, good for a three-day total of 200.
He had an up-and-down round, bogeying three times but saving himself with a 55-yard eagle on No. 11.
The trio will tee off at noon today.Follow Gazette sports reporter Mike Meiler on Twitter @mikemeiler for updates on the local sports scene.