The Red Storm used a late run to take control, and then hung on to beat Detroit 77-74 on Tuesday.
Harrison was kicked out of practice, played limited minutes in the first exhibition and none in the second for not showing the leadership qualities coach Steve Lavin says he needs from the sophomore guard. He is the most experienced player on the youngest team in Division I.
Lavin was upset with Harrison's body language after calls by officials or if things went wrong on the court.
"I think I did a really good job and didn't react to anything," said Harrison who came off the bench to lead the Red Storm with 22 points. "It's just keep taking steps."
Lavin had a smile on his face when he talked about Harrison.
"Across the board I was really impressed," Lavin said. "D'Angelo, from the time we threw him out of practice and took away his starting position, he's been outstanding. The kids have really responded to tough love. Sometimes it works, sometimes it doesn't. Just like being a parent."
Obekpa, a member of St. John's highly regarded recruiting class, had a stat line that would make anybody who is known for their defense proud. The 6-foot-9 native of Nigeria finished with seven points, 11 rebounds and a school-record eight blocked shots.
"I didn't learn it. I just play basketball," Obekpa said of his ability to block shots. "It's a gift. It was fun so I kept doing it."
Lavin said Obekpa is "unique. His length and timing is a central intelligence in motion and he doesn't pick up fouls. Usually kids will be offbalance when they block a shot. Not him. That's intelligence, understanding angles and taking away airspace."
It wasn't a perfect day all around for the Red Storm (1-0). They trailed 37-29 at halftime and Detroit (1-1) led 60-53 with 9:20 to play.
"We were uneven in our play but ultimately found a way to get a gritty win," Lavin said. "That stretch from when we were down 60-53 they only managed four points over 7 minutes against our matchup zone. It was very effective because of our length."
The Red Storm finished the game on a 24-14 run but things weren't settled until Detroit took advantage of a couple of last-minute turnovers to get within three points. Juwan Howard Jr.'s 3-point try to tie at the buzzer was short.
Phil Greene added a career-high 20 points, while Amir Garrett had 15 points and 11 rebounds for the Red Storm
"It came down to the last possession," Detroit coach Ray McCallum said. "With our young team going on the road, we battled back and we had some good stretches early. They made their run and the bottom line is we couldn't hold them off."
The game was part of ESPN's yearly marathon, 24 consecutive hours of college basketball.
St. John's took its first lead since 25-23 when Sir'Dominic Pointer scored on a drive to make it 64-62 with 4:39 to play. That shot capped an 11-2 run during which the Titans managed one field goal -- a drive by McCallum -- in six possessions.
Detroit had scored 11 straight points to take a 34-25 lead with 2:04 left in the first half, and the Titans were up 37-29 at halftime despite shooting just 33.3 percent. The Red Storm weren't much better, hitting 37.5 percent.
St. John's shot much better in the second half (57.1 percent), but turnovers (15) became a big problem, and the Titans were able to turn them into 17 points.
Still, the Red Storm were hanging around, and a 7-0 run capped by two free throws by Garrett made it 60-60 with 6:39 to play. St. John's was able to extend the lead to 75-69 on two free throws by Greene with 17 seconds left.
"The move that Steve (Lavin) made by bringing Harrison off the bench really got them going," coach McCallum said. "He put points on the board. He made play after play down the stretch. He showed what kind of key player he is for them."
McCallum, the Horizon League preseason player of the year and the son of the Detroit coach, finished 8 of 23 from the field, including 4 of 12 from 3-point range.
"We had to have collective awareness where McCallum was on the court," Lavin said. "We made him work and that showed in 8-for-23 shooting . We kept rotating bodies on him. You can't stop a great scorer but you can make him work."
Lavin returned after coaching just four games last season because of prostate surgery. The Red Storm were 13-19 last season under assistant coach Mike Dunlap, now the coach of the Charlotte Bobcats.
"So much of the way I feel is so much of feeding off the team's synergy," Lavin said. "I feel good because this team found a way to get a gritty win and that does wonders for coaches."
The previous record for blocks at St. John's was seven by Robert Werdann in 1979.