It was a somnambulant, sloppy bunch that came out wearing Georgetown jerseys Saturday at Verizon Center. And for 20 minutes, a pressing, opportunistic Mount St. Mary’s team made the Hoyas look pedestrian, raining three-pointers over their lanky frames at one end of the court and forcing turnovers at the other.

“I didn’t recognize the team that was on the court,” Georgetown Coach John Thompson III said of his squad, which toppled No. 11 UCLA and forced top-ranked Indiana to overtime earlier in the week.

It took a halftime sermon on intensity to rouse the Hoyas from their slumber, and they closed in commanding fashion, holding the Mountaineers to just 18 second-half points and prevailing, 72-50, in a game that was closer than the score indicated.

Georgetown (4-1) got double-doubles from sophomore forwards Otto Porter Jr., who finished with 17 points and 13 rebounds, and Greg Whittington, who scored 17 points and grabbed 11 boards. Junior guard Markel Starks and center Mikael Hopkins also managed double figures, scoring 15 and 13 respectively.

But the hot-and-cold approach wasn’t what Thompson wanted to see in the Hoyas’ final tuneup before their home game against Tennessee (3-1) on Friday. Georgetown committed 11 turnovers and allowed six three-pointers in the first half, muddling through for a 34-32 halftime lead over an undersized team with outsized belief.

Rashad Whack, a 6-foot-2 transfer from George Mason who sat out last season to get a chance to compete for Mount St. Mary’s, said his team felt confident it could compete with Hoyas.

“The only thing different is their laundry,” said Whack, who led Mount St. Mary’s (1-3) with 11 points.

While the Hoyas staved off the upset, opening the second half with a 10-2 run and closing on a 22-6 run, the precarious nature of the contest prevented Thompson from spreading playing time around as he would have liked. Without a comfortable lead, which would have given him a chance to blend in reserves who need experience before Big East play begins, Thompson leaned almost exclusively on his starters, bringing only D’Vauntes Smith-Rivera (17 minutes) and Jabril Trawick (13 minutes) off the bench.

“That is not how I wanted today to be,” Thompson said. “We’ve got some guys — from Moses [Ayegba] to Stephen Domingo to Aaron Bowen to Bradley Hayes — that we need to get ready. But it was an eight-point game with five or six minutes to go.”

A crowd of 7,467 Hoyas partisans turned out at Verizon Center with every expectation of an easy victory. Georgetown hadn’t lost a home game to Mount St. Mary’s since 1935.

But under first-year coach Jamion Christian, the Mountaineers play an attacking style known as “Mayhem” that presses on defense, pushes the ball on offense and shoots three-pointers like mad. And it rattled the lackluster Hoyas, who turned over the ball three times in the first three minutes.

Mount St. Mary’s knotted the score at 19 on back-to-back three-pointers and kept the defensive pressure on, as Georgetown’s ballhandlers overthrew passes, got stripped, traveled and dribbled the ball off their feet.

Georgetown never led by more than four until 2 minutes 56 seconds remained in the first half. Porter’s layup put them up 29-23.

Whack answered with successive three-pointers. And on its 11th turnover and a squandered final possession, Georgetown exited for the locker room with a 34-32 lead.

The Hoyas finally brought their front-court advantage to bear in the second half, getting high-percentage baskets from big men Hopkins, Porter and Nate Lubick.

And with Georgetown ramping up its zone defense, the Mount’s shooting went cold, dropping from 42 percent in the first half to 26 percent in the second.

Hoyas note: Georgetown shares Florida’s interest in completing the teams’ season opener, which was canceled at halftime on Nov. 9 because of hazardous, damp conditions on the USS Bataan, Thompson confirmed. But numerous logistical hurdles remain, among them deciding whether to play a full or half game, choosing a neutral site and finding a mutually convenient date before conference play begins for either team.