GREENVILLE, S.C.—Every time it looked like Troy might threaten to slice the Blue Devil lead to just a few possessions, Duke needed a quick response to maintain a sizable cushion against its feisty Round of 64 opponent.

And although he is no longer in the starting lineup, Grayson Allen had no problem stepping up to ensure the Blue Devils preserved their early advantage.

After the Trojans cut Duke's 15-point lead to seven late in the first half, Allen capped a 7-0 run before halftime with a 3-pointer from the top of the key and ignited a 9-0 spurt in the second half that put the Blue Devils up 18 with about 12 minutes remaining. For the second time in three games, Allen made his first four 3-pointers as Duke's red-hot start carried the second-seeded Blue Devils to an 87-65 victory against No. 15 seed Troy at Bon Secours Wellness Arena Friday evening.

“We had to play well, or else we would have gotten beat…. I was pleased with that first performance of ours,” Duke head coach Mike Krzyzewski said. “[Allen] was terrific—he gave us a huge lift and a [3-pointer] at the end of the half. It seemed like whenever we needed a bucket, he got it.”

The junior finished with 21 points and was one of four Duke players in double figures with the Blue Devils taking advantage of their size by shooting over the top of smaller Trojan defenders. Duke's defense had some lapses, but the Blue Devils executed well enough to punch their ticket to the Round of 32, where they will face seventh-seeded South Carolina at about 8:40 p.m. Sunday.

Despite a poor shooting day, freshman Jayson Tatum held his own inside to finish with a double-double with 18 points and 12 rebounds. It was the first double-double by a freshman in a Duke NCAA tournament opener since Danny Ferry did it in 1986. 

The St. Louis native used his length to control the paint, adding four blocks and four steals and excelling as the Blue Devils used a zone defense to slow Troy down in the final 12 minutes. Duke held the Trojans to just 5-of-23 shooting from 3-point range and forced its two best players Jordon Varnado and Wesley Person into 13 turnovers.

“We were just talking more. That's what Coach emphasized the first half,” Tatum said. “Guys weren't talking on the defensive end. We really paid attention to that in the second half.”

The Blue Devils (28-8) were sharp offensively from the get-go, jumping out to a 16-4 lead fueled by a hot start from senior Matt Jones and efficient long-range shooting. Duke's 2-2-1 zone press also rattled the Trojans (22-15) early on, as the Blue Devils took advantage of five early Troy turnovers.

Even with leading scorer Luke Kennard shooting just 3-of-12 for eight points—his lowest scoring output since Jan. 7—Duke made seven of its first 10 3-pointers and finished 13-of-28 from long distance.

“We did a really good job of moving the ball around,” Allen said. “We did a good job kicking it and moving the ball fast, so when the ball is moving like that, the shots tend to go in.”

The Trojans trailed by as many as 15 early on but found their footing once Duke's defensive intensity dipped, led by Varnado. Although he committed seven turnovers, Varnado was extremely aggressive attacking the rim and finishing with 18 points and 10 rebounds to help get his team back within striking distance.

When it looked like the Blue Devils would pull away, Varnado and company fought back, staying within nine until Jones—who scored more than 10 points for the first time since late January—and Allen started Duke's 9-0 spurt.

“When we are hitting like that, we are really dangerous, but we have to keep playing defense,” said graduate student Amile Jefferson, who became the team's all-time leader in games played. “We won that game because we started getting stops—that’s how we were able to extend the lead.”

Despite earning the convincing win, the Blue Devils still have a few things to clean up. Duke missed seven of its first 17 free throws to let Troy hang around at different points and went more than six minutes without a field goal midway through the second half—the Blue Devils might not be able to afford similar miscues if they hope to advance to the Sweet 16.