The Tar Heels (7-4, 4-3 Atlantic Coast Conference) were hanging onto a 20-13 lead when they stopped Kevin Parks for a 2-yard loss on fourth-and-goal from the 1. They then drove 97 yards in 12 plays, Renner capping the march with a 23-yard pass to a wide open Giovani Bernard over the middle for the TD.
A 5-yard completion to Erik Highsmith on fourth-and-2 came on the play just before the touchdown pass, and after Virginia (4-7, 2-5) was forced to punt on the ensuing possession, Renner's 20-yard TD pass to Highsmith finished it.
The Cavaliers had won two in a row and were hoping to win two more to qualify for a bowl game. They shut down Bernard, the ACC's runaway rushing leader, but were picked apart by Renner's precise passing.
He finished 29 for 36 for 315 yards and three touchdowns. His favorite target on the night was freshman Quinshad Davis, who caught an ACC-record 16 passes for 178 yards.
The game looked as if it might become a classic in the oldest rivalry in the south, then turned quickly when the same North Carolina defense that allowed 68 points to Georgia Tech last Saturday made a huge play.
The Cavaliers drove to a first-and-goal at the Tar Heels 8. A draw play by Michael Rocco gained 5 on first down, and runs by Perry Jones and Kevin Parks gained a yard each. But on fourth-and-goal from the 1, Parks was thrown for a 2-yard loss.
The Tar Heels followed with their big drive and, when Darius Jennings got behind the secondary and Phillips Sims floated a certain 81-yard touchdown pass into his hands on third-and-13, Jennings juggled and dropped it. The Cavaliers punted, and five plays later, Renner to Highsmith made it 34-13.
The tandem also teamed up on 9-yard touchdown pass to open the scoring.
The Cavaliers squandered several chances, managing only a field goal after Bernard fumbled a punt at his own 12 and Virginia recovered, and then when they came away with nothing near the goal line.
Virginia trailed 14-3 early but closed to 14-10 on a nifty third-down scramble by Sims, who avoided a sack, rolled right and found Jennings in the end zone from 9 yards out. Sims also had a 13-yard run on third-and-9 at the start of the drive, and Parks powered for a yard to convert on fourth-and-1.
The Tar Heels answered by driving to the Cavaliers 15, where Renner was sacked by Brent Urban for an 8-yard loss on third-and-13. Thomas Moore tried a 40-yard field goal, but missed wide right.
Sims' lone series had produced Virginia's lone touchdown to that point, but in Virginia's quarterback rotation that coach Mike London described this week as ''random,'' the coaches sent Rocco back out for the next series, and his first pass was picked off by Tre Boston, who returned it 36 yards for a touchdown.
The Tar Heels' first two touchdowns came as Renner picked apart a defense geared to stop the run.
He hit Davis for 25, 10 and 20 yards in a 91-play drive that ended with his 9-yard touchdown pass to Highsmith, and he hit Davis for 32 yards on the next drive. Davis also drew a 15-yard pass interference call when cornerback Demetrious Nicholson latched onto him from behind on a throw to the end zone.
That set up North Carolina at 3, and A.J. Blue ran it in on the next play.
Renner was 19 for 23 in the half for 201 yards, and Davis had 10 catches for 130 yards.