Virginia Tech’s Nickeil Alexander-Walker drives past Saint Louis forward D.J. Foreman during the first half Friday night. (Kyle Terada/USA Today Sports)

Virginia Tech Coach Buzz Williams was transfixed by a stat sheet as he walked off the floor at halftime of the Hokies’ 66-52 win over Saint Louis in the first round of the NCAA tournament Friday night. He ignored a couple of fans angling for high-fives near the tunnel entrance at SAP Center and for a split second turned toward the men’s bathroom instead of his team’s locker room. He continued to glue his eyes to the sheet as an assistant steered him to his destination.

Williams had to like what he saw. His team led by 22. It had held the Billikens to paltry 7-for-21 shooting, including 1-for-9 from three-point range. Saint Louis had nearly as many turnovers (12) as points (18). Maybe the most promising part, aside from the Hokies shooting 55 percent to start the game, was that senior point guard and former All-Met Justin Robinson had played more than 10 minutes in his first action back after missing 12 games with a foot injury. He didn’t look fully 100 percent healthy, but within the first 20 minutes Robinson tossed up an alley-oop, came up with two crafty steals and sacrificed his body with a charge in a blowout.

Those were promising signs for the Hokies, who won their first NCAA tournament game since 2007.

“There was a little rust,” Robinson said. “The first game to get rust off and just get back out there is a good thing for me.”

As the No. 4 seed in the East Region, Virginia Tech was expected to advance. Even with a sloppier second half — Saint Louis pulled within 10 at one point — this was an ideal tone-setter for a Hokies team that has ambitions of making a deep run, especially on a day when each of the underdogs at this site won, with No. 13 seed UC Irvine beating Kansas State and No. 12 Oregon blowing out Wisconsin in the South Region. And, another No. 12 seed, Liberty, rallied to upend Mississippi State for its first NCAA tournament win in school history.

The Hokies will meet the Flames in the second round ­Sunday.

“We kind of predicated as a team that we were going to end up playing Liberty, because we thought they were going to get overlooked by Mississippi State. And that’s kind of what happened,” Robinson said. “We just know they’re a good team.”

The most pressing question Friday night concerned Robinson, who hadn’t played since Jan. 30 and handled questions this week about his workload as he reacclimated himself back into the team’s routine. Williams was forced to run dummy offense in practice so the rest of the players could get used to playing with Robinson again, usually an exercise reserved for the early stages of the season, not late March.

Robinson didn’t start Friday night, but he didn’t need to, either. Early on, the offense was crisp behind 19 combined points from Kerry Blackshear and Nickeil Alexander-Walker. Robinson didn’t sub in until more than six minutes were gone. Within the first couple of minutes, he recorded a steal and assisted on that alley-oop dunk, finished by Ahmed Hill. His first three-pointer made it 26-8, and by the time he hit another layup in the final two minutes of the half, Virginia Tech was cruising. Robinson came up with another steal later in the half, then took a charge with his team leading by 20.

“I think everybody was excited to be out there together. It was the first time we had the entire unit together [since Jan. 30],” forward Ty Outlaw said. “There was no egos, no personal agendas. Everybody just wanted to do what it took to win and get out of the first round.”

Alexander-Walker finished with a game-high 20 points, Blackshear added 15, and Robinson chipped in nine.

The most promising part of the night for Saint Louis came after Williams and the Hokies returned from the locker room. The Billikens used a 6-0 burst to start the second half, and Williams immediately told Robinson to get off the bench and check into the game. Robinson assisted on a three-pointer by Alexander-Walker on the Hokies’ first possession after he returned to push the lead back to 17. Alexander-Walker then scored four points in 21 seconds to make it a 20-point lead again. By that point, Virginia Tech — a team that had relied on the deep ball all season long — had taken just eight three pointers on the night and had 30 points in the paint.

Saint Louis pulled back within 10 points with just over 10 minutes remaining as Virginia Tech’s offense went without a field goal for more than five minutes. But the Hokies remained in control by attacking the rim from the free throw line, and Alexander-Walker finally connected on a field goal with 6:58 left to give his team a 15-point lead.

The scariest moment of the night may have come when Robinson appeared to slip on a wet spot on the floor. He may have not been at full strength Friday night, but he climbed to his feet to avert disaster.

That was more progress for Robinson, who will have a chance to take another step in his return Sunday against Liberty.

“I felt good. I thought my wind was going to be way worse than it was,” Robinson said. “I think being able to play this game and get a little rust off will help us with the next round.”