Mark Turgeon leaned back in his chair courtside and stomped the ground, almost pitching a tantrum at another loose ball that went unclaimed by his Maryland basketball team. As fast as the Terrapins’ bubble filled, inflated after Saturday’s thrilling win over Duke, things abruptly popped on the road.

If last weekend’s loss to Virginia was “rock bottom,” in Turgeon’s words, the second-year coach might want to check his depth perception. The Terrapins were outhustled and outplayed by host Boston College in a 69-58 loss Tuesday night, reverting to bad habits and suffering major damage to their postseason chances.

“Really disappointed in our effort, in our ability to play with a little heart and more desire in a big game,” Turgeon said. “Sitting over there, it was hard to watch.”

The Eagles (12-14, 4-9 ACC), who had lost to both No. 2 Miami and No. 6 Duke at home by one point this season, scored points on eight straight second-half possessions, including a whopping 12 made free throws during that span. Maryland (18-8, 6-7), which looked the part of an NCAA tournament participant in downing the Blue Devils and sparking the second court-storming of its season, fell hard down the stretch. Only Logan Aronhalt, who notched a season-high 26 points on seven three-pointers, provided any semblance of offense for the Terps.

No other player scored in double figures. Alex Len shot just 1 for 5 from the field and fouled out with 38.5 seconds left. Seth Allen, the hero against Duke, was 2 for 8 from the field.

The Post Sports Live crew debates the number of ACC schools likely to get an NCAA tournament bid. (Post Sports Live/The Washington Post)

Olivier Hanlan had 26 points for Boston College.

A fervent pace early did little except accelerate the possession rate. Both teams mustered just two points by the under-16 media timeout and withstood seven tied scores in the first half. Shortly after Patrick Heckmann stuck a layup, Aronhalt took over, hitting three straight three-pointers in a 50-second span to boost the Terps to a 33-26 margin at halftime.

Dez Wells sent Maryland into the break with a monstrous buzzer-beating block of Boston College guard Joe Rahon, who picked Allen on the other end and broke away for an apparent uncontested layup. The hyper-athletic Wells telegraphed the rejection from midcourt, tearing through the lane and smacking Rahon’s shot off the backboard. As the ball ricocheted away, Turgeon bounded off the bench and pumped his fists, leading the Terps into the locker room. It was the last time he celebrated a play.

The intensity never carried over into the second half. Boston College opened on a 6-0 run, chopping the lead to 33-32 after a Rahon three-pointer in transition. On the sidelines, Turgeon’s barks echoed throughout the disengaged arena. After reserve Eddie Odio tipped in a second-chance effort, the Eagles had their first lead since going up 7-4 in the first half. Boston College ballooned the lead to five points following a Hanlan layup, capping off a 6-0 run and forcing Turgeon to burn two timeouts before the under-12 media timeout.

“Starting the second half, we just weren’t there,” Aronhalt said. “We had the lead going into halftime, Dez had the big block, and we just came out flat in the second half. I wish I knew why. I’ve been thinking about it since the game’s been over. And I have no idea. No idea.”

Riding the emotional highs spurred by their 83-81 win over Duke, undoubtedly the pinnacle of Turgeon’s tenure in College Park thus far, the Terps headed north looking to avoid precisely the letdown suffered at North Carolina, when the Tar Heels bludgeoned a team coming off its court-storming victory against North Carolina State.

Instead, Maryland succumbed to a field-goal drought of over seven minutes in the second half. The Terps were outrebounded for the second time all season, 37-32, and were dominated by Odio, who finished with 11 rebounds, eight points and six blocks. By the time Odio stuffed Len at the rim with less than two minutes left, eliciting chants of his name from the student section, the Eagles were well on their way.

“I just don’t get it,” Turgeon said. “I just don’t understand. We’re right here, it’s a big game. It’s not a hostile environment. You just got to want it. And it seemed like we were standing in quicksand all night, standing and watching.”