Alexander-Walker, a heralded freshman, finished with 24 points in his Virginia Tech debut and opened the second half with five quick points, igniting a run for the Hokies. Kerry Blackshear Jr. scored 23 points for Virginia Tech.
Virginia Tech led 73-53 on a dunk by Alexander-Walker with 13:55 to play. The Hokies were not challenged down the stretch.
Kameron Chatman scored 23 points to lead the Titans, who are expected to be improved after suffering through an 8-23 campaign last year.
The Hokies led throughout the first half, but struggled to distance themselves from the Titans, who got 18 points from Chatman to stay close before intermission.
Blackshear converted a traditional three-point play in the final minute of the first half, helping the Hokies build a 52-42 lead at halftime.
Coach Buzz Williams enters his fourth season at Virginia Tech with hopes of taking the Hokies back to the NCAA Tournament for a second straight season. Virginia Tech reached the NCAA Tournament last season for the first time since 2008, but must replace its two leading scorers off that team.
The return of forward Chris Clarke from injury should help. Clarke tore the ACL in his left knee in February, but was back on the court for the Hokies on Friday. He finished with nine points.
The championship rounds of the 2K Classic, which benefits the Wounded Warrior Project, will take place Nov. 16-17 at Madison Square Garden in New York. Virginia Tech will face Saint Louis in one semifinal.