The first leg of the postseason for the George Washington men’s basketball team ended Saturday in the Atlantic 10 tournament semifinals, where the third-seeded Colonials were unable to contend with second-seeded Virginia Commonwealth’s frenetic pressure defense in the second half of a 74-55 loss at Barclays Center.

Even though they failed in their quest for their first conference title since 2006-07, the Colonials departed Brooklyn at least with the consolation that they are all but ensured of an at-large berth in the NCAA tournament following a resurgent season in which they have matched the second-most wins in program history.

“I told the guys before the game: ‘Hey if we win, we’ve got to prepare for tomorrow. If we lose, I’ll be miserable for a few hours,’ ” GW Coach Mike Lonergan said. “I told them I’d try to make it an hour. I’ll sulk for a while, but I’ll wake up tomorrow, and it will be a great day in my life. They talk about getting in the tournament, but hey, we’re getting in the tournament unless everybody is wrong.”

VCU will play fourth-seeded Saint Joseph’s, a 67-48 winner over ninth-seeded St. Bonaventure, in Sunday afternoon’s final.

Senior forward Isaiah Armwood led GW (24-8) with 15 points and six rebounds, and senior forward Namanja Mikic had his second straight productive game from three-point range, making 4 of 7 for 12 points. Sophomore forward Kevin Larsen (Montrose Christian) chipped in 10 points and four rebounds but committed a game-high six turnovers for the Colonials, who had 15 as a team and shot 33 percent in the second half as it lost for the first time in five games.

The 23rd-ranked Rams (26-7) extended their halftime lead to five shortly after the break when Treveon Graham scored seven consecutive points on a three-pointer, a layup and a jumper. Lonergan appeared ready to call a timeout, but Patricio Garino collected an offensive rebound and dunked and then made two foul shots on the next possession to stem the run.

The Colonials closed the gap to 46-45 with 14 minutes 58 seconds left in regulation on a steal and layup by sophomore point guard Joe McDonald (Landon), but they went scoreless over the next six minutes until Larsen’s dunk on an offensive rebound. That basket drew GW within 50-47.

But VCU got another three-pointer from Rob Brandenberg at the shot-clock buzzer, and when Graham (St. Mary’s Ryken) added another three-pointer, the Rams were in front 60-51 with 5:39 to play. The lead grew to 64-53 when Briante Weber, the Atlantic 10 defensive player of the year, made both ends of a one-and-one and Mo Alie-Cox scored on a rebound follow.

The first half featured the first playing time in two months for GW sophomore guard Kethan Savage (Episcopal), who broke his left foot Jan. 18 in a 79-71 win against Saint Bonaventure. The Colonials’ second-leading scorer missed the final 12 games of the regular season and Friday night’s 85-77 victory over Massachusetts in the Atlantic 10 quarterfinals.

“I mean it was awesome,” Mikic said of seeing Savage on the court even if it was for only one minute. “He kind of carried us through for the first half of the season. He’s really improved this whole year. We were really sad to see him go down, and for the last eight weeks we were waiting for this moment.”

While GW welcomed back one of its former starters, the Rams lost one of their most important contributors in Melvin Johnson. The sophomore guard went down while trying to contest a loose ball against GW’s Nick Griffin and was unable to get up while Mikic sank a three-pointer at the other end to give the Colonials a 12-9 lead.

Officials whistled for a stoppage at 15:30 immediately after that basket, and VCU Coach Shaka Smart and team trainers came onto the court to attend to Johnson, who was grimacing in pain and clutching his left knee. The Rams’ top three-point shooter had to be helped to the locker room and came back to watch the second half with his left leg wrapped.

“Early in the game we made all the right plays,” Armwood said. “It was a turning point in the game where it wasn’t necessarily them. We just kind of turned the ball over, some uncharacteristic turnovers, and they took the lead going into halftime, and it continued in the second half.”