Vander Blue scored the game's final four points, including a driving layup as time expired, as 15th-ranked Marquette outlasted St. John's in a 69-67 overtime thriller in the regular-season finale for both teams.
Blue finished with 16 points and Jamil Wilson added 14 along with eight rebounds for Marquette (23-7, 14-4 Big East), which overcame 19 turnovers and blew a 10-point lead with three minutes left in regulation to enter next week's Big East Tournament on a four-game win streak.
The Golden Eagles had already sewn up one of the four double-byes for the event and will return to MSG for a quarterfinal matchup on Thursday. Marquette will be the third seed following Louisville's win over Notre Dame on Saturday.
Playing without both leading scorer D'Angelo Harrison and starting forward Sir'Dominic Porter due to suspensions, the Red Storm (16-14, 8-10) scored nine straight points to force overtime before ultimately suffering their fourth straight loss and sixth defeat in seven outings.
Phil Greene IV led the St. John's comeback effort with 20 points, with Jakarr Sampson finishing with 17 in the setback.
The Red Storm will be seeded 10th in the Big East Tournament and take on Villanova in Wednesday's second round.
"Nobody in our locker room is satisfied with moral victories," St. John's coach Steve Lavin said. "We'll try to build on the positives and improve upon the areas that hurt us in this game and get ready for the Big East Tournament. Everyone is 0-0 when championship week begins, it's a fresh start and a new beginning."
Blue hadn't scored since the four-minute mark of the second half before taking over during crunch time. The play-making guard first knifed through the lane and scored to forge at 67-67 tie with 48 seconds left in OT, then had the ball in his hands following a Marquette timeout that came after the Golden Eagles got possession after the rebound of Greene's missed 3-point try landed out of bounds with 16 seconds on the clock.
After taking the inbounds feed, Blue dribbled near the top of the key before blowing by a St. John's defender and putting up an off-balance shot that swished through as the final horn sounded.
"I wanted to make sure it was the last shot," Blue said. "I didn't want St. John's to get a shot. I didn't want a charge or to turn the ball over in any way."
Marquette held a 61-51 lead after Wilson made 1-of-2 free throws with 3:23 left in regulation, but mustered only a pair of successful foul shots over the duration of the second half as St. John's came storming back.
Greene began the rally with a layup that pulled the Red Storm within 63-56 with 1:48 remaining, and Marco Bourgault buried a 3-pointer on St. John's ensuing possession before Felix Balamou's tip-in made it a two-point game entering the final minute.
After Marquette's Junior Cadougan missed a layup try, Branch raced down the court and converted with 27 seconds showing to tie the score at 63-63.
The Golden Eagles then failed on an opportunity to win in regulation by turning the ball over without attempting a shot.
After the teams traded baskets to begin the extra session, St. John's Chris Obekpa broke a 65-65 deadlock with a second-chance putback with 2:02 to go. The Red Storm couldn't add to the margin, however, and Blue delivered the first of his late-game makes to draw Marquette even.
St. John's had built a 23-15 lead with eight minutes remaining in the first half on the strength of a 9-2 run, but the Golden Eagles came charging back over the latter stages of the opening period. Marquette closed out the frame on a 13-2 burst as the Red Storm went cold offensively, with Cadougan's 3- pointer 37 seconds prior to intermission sending the visitors into the break owning a 28-25 edge.
The Golden Eagles then caught fire to begin the second half, hitting their first six shots during a 13-2 sequence that extended their cushion to 41-27 three minutes into the period.
St. John's battled back to move to within 52-48 on Greene's jumper with a little under six minutes left, but an 8-3 spurt highlighted by treys by Wilson and Blue put the Golden Eagles up by nine two minutes later.
Porter was serving a mandated one-game suspension for fighting with Notre Dame's Cameron Biedscheid in Tuesday's 66-40 loss to the Fighting Irish, while the university banned Harrison for the remainder of the season for undisclosed violations last week ... St. John's went just 2-of-16 from 3-point range and 5-of-13 from the free throw line ... Marquette posted their fifth straight road victory in the series and have taken nine of 10 matchups between the schools since joining the Big East in 2005 ... St. John's fell to 2-7 this season against Top 25 opponents.