PITTSBURGH -- Collin Sexton scored 21 of his team-high 24 points after halftime to lead Alabama to an 86-83 victory over Virginia Tech on Thursday night for the Crimson Tide's first NCAA Tournament win in a dozen years.

John Petty kept ninth-seeded Alabama (20-15) in it while Sexton struggled during a sluggish opening half and finished with 20 points while shooting 6 of 8 on 3-pointers. Sexton found a rhythm in the second half, including a handful of big shots over the final five minutes to give the Crimson Tide a bit of breathing room in a game that featured 10 lead changes, with no team ever being up by more than seven points.

Alabama will face top-seeded Villanova in the East Region's second round on Saturday. The Wildcats had little trouble dispatching Radford earlier Thursday.

Things weren't nearly as easy for the Crimson Tide, who needed their freshman backcourt mates and a serious uptick in defensive intensity in the late going to advance to the second round for the first time since 2006.

Sexton and Petty were in elementary school back then. Now they're the centerpiece of coach Avery Johnson's dynamic attack with the Crimson Tide. Alabama shot 61 per cent (14 of 23) from the floor in the second half, including a 17-footer from Sexton that hit the back of the rim and dropped in to put the Crimson Tide up 70-64 with 5:11 to play.

He knocked down a turnaround jumper with 1:35 remaining to push Alabama's advantage to 77-72.

Justin Robinson and the eighth-seeded Hokies (21-12) kept coming. Robinson finished with 19 points but was called for an offensive foul with 48 seconds remaining and Virginia Tech down 78-74. Hokies coach Buzz Williams earned a technical foul after throwing paper onto the court in frustration. Sexton made one of two free throws and then added two more on Alabama's ensuing possession to give the Crimson Tide just enough of a cushion.

Alabama needed a couple of wins in the SEC tournament, including an upset of rival Auburn, to reach the NCAAs for the first time in seven years. Eager to prove they were deserving of the bid, the Crimson Tide received a boost in pregame warmups when forward Donta Hall ran onto the court with his teammates less than a week after sustaining a concussion in a victory over Auburn.

Hall finished with 10 points and three rebounds in 25 minutes, but it was the play of Sexton and Petty that pushed the Crimson Tide into the round of 32.

The Hokies, making consecutive NCAA appearances for only the third time in program history, have taken a far more balanced approach under Williams. Virginia Tech came in with six players averaging at least 8.3 points and spread it around during a blistering first half in which it took a slim 43-41 advantage. Four different Hokies made 3s in the first 20 minutes and Virginia Tech went 7 of 9 from deep.

Yet Alabama hung around even with Sexton limited to a single bucket. Petty picked up the slack. The freshman has been streaky at times this season -- he went just 3 of 19 on 3s during a four-game stretch prior to a slump-busting 18 points in an SEC tournament loss to Kentucky.

BIG PICTURE

Alabama: Sexton might be the thinking man's version of Oklahoma star point guard Trae Young. Sexton lacks Young's shooting touch, but his quickness makes it nearly impossible to keep him out of the lane. And rather than force shots late, Sexton tried to get to the rim.

Virginia Tech: The Hokies are on the rise in the Atlantic Coast Conference, but success in March remains elusive.

UP NEXT

Alabama will try to reach the Sweet 16 for the first time since 2004 when it takes on Villanova.