CHARLOTTESVILLE, Va.—For most of Wednesday night, Duke’s offense was ineffective, struggling to attack the basket and find open shots against No. 14 Virginia’s pack-line defense.

With less than three minutes remaining in the game, before Jayson Tatum drilled deep 3-pointers on back-to-back possessions to put the game away, the Blue Devils had just 48 points. But they still led by four at that point thanks to their most complete defensive performance of the season.

Although the Cavaliers entered the game as the second-lowest scoring team in the ACC due to their slow pace of play, they were still the most efficient shooting team in the league at 49.2 percent. Instead of finishing long possessions with easy shots in the paint, though, Virginia had to force up several contested shots with the shot clock running down against Duke’s stifling defense and wound up just 21-of-57 from the field.

“Virginia is a great offensive team. They take their time. They make sure they get a good shot every time down the court,” sophomore Luke Kennard said. “We needed to lock in on the defensive end tonight. That was our main priority and we did a great job of that.”

The Blue Devils did most of the damage even without graduate student Amile Jefferson—their defensive anchor down low—on the floor. The Philadelphia native picked up his fourth foul with more than 15 minutes left in the game and played just 21 minutes due to foul trouble, forcing freshman Harry Giles into a large chunk of meaningful minutes.

Giles met the challenge, notching two steals in quick succession with Duke clinging to a 35-32 lead. The Cavaliers did not score for more than three minutes after the 6-foot-10 big man entered the game.

“Harry played magnificent. I believe Harry is getting better each and every game,” Kennard said. “Amile is our backbone on the team and we needed Harry to step up. He played big minutes for us, got some stops, some buckets.”

Giles, thought of more often as a skilled offensive threat than a gritty rim protector, scored five points and played more minutes than he has since Jan. 14, making most of his impact on defense. Virginia’s starting frontcourt of Jack Salt and Isaiah Wilkins combined to score just eight points and rarely got the ball in good position in the paint.

“Offense is going to come. It is what it is. It’s going to take time,” Giles said. “I’m just going to do what I do…. I’m going to be protecting the rim, stealing the ball.”

On the perimeter, Cavalier point guard London Perrantes exceeded his scoring average with 14 points, but needed 11 shots to do it. Last year’s ACC leader in 3-point percentage, he also made just one of his five attempts from long range.

Blue Devil defensive stopper Matt Jones drew the assignment on Perrantes to start the game and kept him in check in the opening minutes. Perrantes took advantage of a matchup against Kennard for a possession by getting to the rim for a layup, but Duke gave him very few straight-line drives to the basket the rest of the way.

In crunch time, after a 3-pointer from Virginia freshman Kyle Guy trimmed the Blue Devil lead to one with less than eight minutes left, Jones was back on Perrantes and shut him down to kill the Cavaliers’ hopes of a comeback.

Virginia went scoreless for nearly five minutes after Guy’s triple, with Perrantes missing a contested 3-pointer in the middle of the drought that would have trimmed the lead to one. And after Perrantes finally made a jumper to pull within four, he was forced to take another deep mid-range jumper on the ensuing possession that bounced harmlessly off the rim.

“Matt’s been the key guy for us. He started on Saturday against [Jaron] Blossomgame and Blossomgame had seven,” Duke head coach Mike Krzyzewski said. “Perrantes is one of the best players in the country and he’s the guy that makes them go. He’s an outstanding leader and player, but he had to work really hard.”

With Duke keeping the Los Angeles native out of the paint, the Blue Devils made the Cavaliers have to shoot well in order to come out on top, but they missed a lot of open jumpers. Virginia’s 36.2 percent clip from the field was a season low, and it shot an uncharacteristic 5-of-20 from beyond the arc.

With Duke now playing its best defense of the season—the Cavaliers’ 55 points were the fewest scored by a Blue Devil ACC opponent this year—Duke now appears to be clicking at the right time.

“We got decent shots for the most part in terms of what we could get against them without being able to throw the ball inside and score,” Cavalier head coach Tony Bennett said. “[We] had a little trouble when we got some open ones or opportunities finishing. They made it hard and that was a good defensive Duke team tonight.”