Blue had touchdown runs of 1 and 13 yards, and Renner finished 17 of 30 for 194 yards with a touchdown pass and a 4-yard scoring run.
Logan Thomas was 26 of 49 for 354 yards with a 13-yard touchdown run and two long touchdown passes. Demitri Knowles took a kickoff 93 yards for a TD for the Hokies, who are off to their worst start since opening 2-3-1 in 1992.
Bernard surpassed his previous best of 165 yards set last year against Duke, and nobody has rushed for more yards against a Frank Beamer-coached Virginia Tech team. Bernard also became the Tar Heels' first 200-yard rusher since Ronnie McGill rolled up 244 against Wake Forest in 2003.
Bernard had two rushes of at least 50 yards - including his 62-yard touchdown on a fourth-and-1 on the first play of the second quarter that put the Tar Heels ahead to stay.
North Carolina began to pull away midway through the third quarter, going ahead 35-20 on the Renner-to-Tapley touchdown pass before Knowles took the ensuing kickoff back for a touchdown.
Virginia Tech went for two, trying to make it a one-score game, but Thomas' pass over the middle didn't have a chance, and the Tar Heels scored the next two times they touched the ball.
Casey Barth kicked field goals of 44 and 40 yards for North Carolina. Its 48 points were the most scored in the series by either team, and the Tar Heels gained at least 500 total yards for the third time under new coach Larry Fedora.
Thomas threw an early 49-yard touchdown pass to Marcus Davis and added a 66-yarder to Corey Fuller with 8:55 left for the Hokies, who lost for just the sixth time in 33 ACC road games.
The Tar Heels entered outscoring their previous three opponents at Kenan Stadium by a combined 155-6 and hadn't allowed a touchdown at home all season. Thomas didn't need much time to end that streak, bursting through on a 13-yard keeper to make it 7-0 barely 2 minutes in.
Tapley then tied it - and started the Tar Heels' scoring binge - by taking the ensuing kickoff back for a touchdown. That was the first kick return for a score against Tech since 1993, the longest streak in the country.