St. John's D'Angelo Harrison, left, and Georgetown's Hollis Thompson vie for the ball in the second half. Thompson scored all 20 of his points after intermission. (Seth Wenig/AP)

Even after misfiring on each of his first six attempts in the opening 20 minutes at Madison Square Garden, Hollis Thompson never doubted his smooth shooting stroke.

Neither did his teammates. They kept getting him the ball, and the junior swingman delivered, scoring all of his team-high 20 points in the second half to help the No. 11 Georgetown men’s basketball team pull away for a 69-49 victory over St. John’s that was easily the Hoyas’ most complete game in three weeks.

“Coming out of halftime,” Thompson said, “you just got to say: ‘Well, none have dropped. But if the last ones haven’t dropped, that means I’ve got one coming soon.’ ”

In addition to Thompson’s second-half barrage, the Hoyas (14-3, 4-2 Big East) were propelled by a tough defensive effort and strong individual performances from senior guard Jason Clark (15 points, eight rebounds, eight assists) and freshman forwards Otto Porter (13 points, 10 rebounds) and Greg Whittington (eight points, eight rebounds) as they ended a two-game losing streak.

“You lose a couple [and] you have to get out of it,” Coach John Thompson III said. “You have to find a way to get out of that rut. Our guys realized the only way to get out of it is with hard work. And our effort today was good.”

Getting out of that rut collectively began with Hollis Thompson getting out of his own personal ditch. The Big East’s top three-point shooter at 52.4 percent, Thompson made five shots from beyond the arc to help the Hoyas break open a close game and force the Red Storm to adjust defensively.

The surge came one game after Thompson was held scoreless in the second half of Monday’s 68-64 loss to Cincinnati. On Sunday, though, Thompson was unstoppable after intermission.

He sank a pair of three-pointers and threw down a dunk in the opening 4 minutes 18 seconds of the second half to give the Hoyas a 35-25 edge. Moments later, he nailed another three-pointer to give the visitors their biggest lead of the game, 40-29.

St. John’s freshman Moe Harkless (21 points, 10 rebounds) and the Red Storm (8-9, 2-4) chipped away at Georgetown’s lead, eventually whittling it down to 48-45. Thompson, though, made a three-pointer from the corner to put the Hoyas ahead, 51-45, with 6:12 remaining.

“We all know Hollis can shoot,” John Thompson III said. “He doesn’t lose confidence in himself and we don’t lose confidence in him. We just have to make sure we get him shots.”

“Hollis didn’t realize that he was oh-fer” in the first half, the coach added with a laugh. “That’s what makes him a good shooter.”

St. John’s, which is 0-7 against ranked opponents, never recovered.

“Hollis got free on us and that made a huge difference,” said St. John’s assistant coach Mike Dunlap, who is filling in for Coach Steve Lavin as the Red Storm’s head coach recovers from prostate cancer. “We were able to control the paint, defensively, in the first half. I thought Hollis was the difference in that he spread out our zone.”