Virginia’s Akil Mitchell dunks in front of Boston College’s Alex Dragicevich. (Steve Helber/Associated Press)

The crowd had already begun streaming for the exits and Virginia’s players were telling jokes on the bench, waiting for the final minutes to tick off the clock. It had been an easy night for the Cavaliers to that point. Too easy, as it turned out.

No. 20 Virginia stormed out to an early lead, pushed it to as high as 21 points in the second half, then nearly fumbled it all away at John Paul Jones Arena on Wednesday night.

That the Cavaliers ultimately emerged with a 77-67 victory over Boston College to continue the program’s best start in conference play since 1981-82 was of little consolation.

“It’s a friendly reminder that takes us back down a notch, that shows us we’re not as good as we think to be relaxing in a game,” guard Malcolm Brogdon said. “We’re still playing ACC competition. Everybody is really good.”

Brogdon was the main reason Virginia (18-5, 9-1) avoided a complete collapse to win its sixth straight. The sophomore finished with his first career double-double and set a career high in rebounds facing the ACC’s worst defensive team this year.

He scored in double figures for the 10th consecutive game, filling up the stat sheet with 17 points, 11 rebounds and seven assists. The Cavaliers also got 39 points from their bench as sophomores Justin Anderson and Anthony Gill contributed 13 points apiece.

“I’m locked in,” Brogdon said. “I don’t even feel like I’m hot. I feel like I’m just playing my game and sticking to my role.”

Brogdon also hit clutch free throws down the stretch, a surprising development after the Cavaliers coasted through the first 34 minutes of action.

Virginia had a 69-50 lead with less than six minutes left in regulation following a three-pointer by forward Evan Nolte (nine points), but Boston College (6-16, 2-7) proceeded to go on a 17-4 surge. The Eagles, who shot just 9 of 27 from three-point range for the game, caught fire from beyond the arc and got a series of easy layins courtesy of forward Ryan Anderson (20 points) and guard Olivier Hanlan (14 points) during the run.

Justin Anderson noted a disjointed second half that featured 31 fouls “made us pull back defensively. We couldn’t be as aggressive as we normally are.” Nonetheless, Virginia’s advantage had suddenly dwindled to 73-67 with 39 seconds remaining.

Brogdon, though, closed the door on a potential comeback, hitting all four of his free throws down the stretch after Coach Tony Bennett was forced to re-insert his starters. Brogdon connected on eight of his nine foul shots, but the rest of the Cavaliers went just 11 of 25 from the line.

After Boston College took an early 3-2 advantage, Virginia used an 18-2 burst in the first half to build a 40-21 halftime lead. The Cavaliers eventually emerged with their eighth double-digit win in 10 ACC games, but this one didn’t come without tense moments late.

“It shouldn’t have gotten to that place if we had taken care of business,” said Bennett, whose team has won 14 straight conference games at home, the second-longest streak in school history. “But it did and we kind of managed to get the right guy at the line.”