At halftime, head coach Oliver Purnell told his players to keep playing how they had been and the shots would start to fall.

“I said at halftime ‘just pick your heads up and keep playing because we will play better offensively, we’re going to shoot better than 21 percent,” Purnell said. “We’ll take a little better care of the basketball and we’ll be fine.”

It worked as DePaul erased a 29- 19 deficit Sunday and took St. John’s to overtime, defeating them 71-67 in a comeback victory. DePaul forward Myke Henry scored 19 points — 13 of those coming after the half — and guard Billy Garrett Jr. added 20 to give the Blue Demons the team’s most Big East wins under Purnell.

DePaul (10-9, 4-2 Big East) scored 52 points after coming out of the locker room, and sealed the game when Henry hit a pair of late free-throws to give the Blue Demons a 69-67 lead with 13.6 seconds left in overtime.

“Shots weren’t falling in the first half and they started to fall in the second,” Henry said. “Coach just said to keep our heads up and to keep playing our game.”

The Blue Demons got off to a sloppy start, going 1-6 from the field and 0-4 from three-point range, as well as turning the ball over twice going into the first media timeout. Purnell burned one of his first timeouts only a minute into the game after the Blue Demon defense let up an easy jumper, the first points of the game.

As the half wound down, the mid-range jumpers that St. John’s was having troubles making started to fall and they raced out to an 8-0 run. The Red Storm matched their early five-point lead with a 24-19 advantage with 2:42 to go in the first.

The Red Storm closed the half on another mini-run, adding five points to their lead and took the momentum into the locker rooms up 29-19. DePaul was shooting just 22 percent from the field and 18 percent from three.

But the Blue Demons found their rhythm, thanks to Henry and Garrett. Henry finished with his second-career double-double, 19 points and 12 rebounds.

DePaul started off the second half well, making some headway into the deficit. Two threes by Aaron Simpson and Durrell McDonald cut the lead to 36-32 going with 15:29 to go.

The teams traded baskets back and forth after being tied at 38. A big moment, however, came for the Blue Demons as the clock continued to tick away. Down 55-53, Simpson knocked down an open three from the corner to put the Blue Demons up by one with 3:09 to go, leading to a timeout.

“We knew that every game comes down to six minutes, we’ve practiced for this,” Simpson said. “It wasn’t really new to us, we knew what to do.”

St. John’s, however, capitalized on a rare free throw miss from Simpson in the final 13 seconds, and Red Storm guard Rysheed Jordan hit a pair of free throws to tie the game. DePaul guard Durrell McDonald missed a last-second three for DePaul and the game went to overtime.

In overtime, the two teams traded baskets in the first couple minutes of overtime until Forrest Robinson hit a three from the corner to put DePaul up by three. Simpson added a free throw to make it a two-possession game, but St. John’s cut the lead in half on the next possession. Jordan then tied it with 42.2 seconds to go.

With 13.6 seconds to go, Myke Henry got fouled driving into the lane and knocked down two free throws to go up 69-67. Chris Obekpa missed a shot on the other end and DePaul rebounded, sealing the victory at 71-67 for DePaul.

The Blue Demons finished the game 25-29 from the line, including a perfect 13-13 from Garrett. It was another win where DePaul sealed it with free throws, and DePaul leads the conference in free throw percentage.

“This was a similar game to all of our home wins,” Purnell said. “If you take care of the basketball and make your free throws you have a great chance to win.”