NEW YORK -- Xavier ended its three-game losing streak with an 82-77 win over St. John's at Madison Square Garden on Sunday, but the No. 24 Musketeers may have lost their star point guard for quite some time.

Edmund Sumner, who leads Xavier (15-6, 5-3 Big East) in assists and is second in scoring, suffered a leg injury and had to be helped off the court after scoring on a layup with six minutes to play and the Musketeers holding a 68-56 lead,

Sumner, third in the conference with 4.9 assists per game, finished with 17 points and 7 assists. Xavier coach Chris Mack didn't have an update on Sumner's condition, only saying that he would undergo an MRI on Monday.

"It didn't look good," said Mack. "Hopefully he (Sumner) will be back sooner than later. I thought the game flipped when Edmund went out."

St. John's (10-13, 4-6) eventually whittled the Xavier lead to 70-68 with four minutes to play, but couldn't get any closer. Freshman Quentin Goodwin replaced Sumner, scoring six points in those final six minutes on his way to a career-best 16 points. He committed just one turnover.

"He (Goodwin) got rattled a little bit," said Mack. "But I don't know how many freshman point guards who can take that pressure, flip it and respond to it. He organized us in the offense, set the plays and defended.

"I'm really happy for Quentin. To step up in a really big stage against two of the top freshman guards (Shamori Ponds and Marcus LoVett) in the country is big."

The Musketeers, who lost those three games to ranked teams -- No. 1 Villanova, No. 11 Butler and No. 19 Cincinnati -- received 17 points and 10 rebounds from forward Trevon Bluiett.

Shamori Ponds paced St. John's (10-13, 4-6) with 23 points. He was 6 of 14 from the floor and 11 of 13 from the line. Marcus LoVett and Bashir Ahmed each scored 11 points for the Red Storm.

Ponds' layup with 17 seconds to go cut the deficit to 80-77, but the Red Storm were forced to foul, and Xavier made two of four free throws to seal it.

Two foul shots and a spinning layup from Goodin followed a short jumper from Bluiett that put Xavier in front 78-70 with 2:03 left.

An 8-0 run in just 55 seconds brought St. John's to within 68-64 with 4:55 to play, and free throws from Malik Ellison and LoVett sliced the difference to 68-66.

"They (Xavier) are one of the top 25 teams in the country and they got us down by 15 points," noted St. John's coach Chris Mullin. "That is something that can balloon to 25, but we got it down to 3. That is progress.

"We could have really got discouraged, but I thought we kept playing, hung around."

Bluiett's 3-pointer gave Xavier its biggest margin, 59-44, at the 9:50 mark.

"He (Bluiett) is playing with a ton of confidence," Mack said. "We needed every bit of his 21 (points) and 10 (rebounds). Trevon has to get better at lot of things for us, now that Edmund might be out a while. He (Bluiett) has to be a defender, he has to be a rebounder, he has to be a guy who handles the ball and makes a lot guys better."

A layup from Ponds enabled the Red Storm to cut the deficit to 39-34 with 16:24 to play, but Xavier responded with a 15-7 run to move ahead 54-41 with 11:04 to go.

St. John's converted just 2 of 12 3-point attempts in the half.

The Red Storm made just one basket in the final 4:22 of the half and trailed 32-25 at the break.

The Musketeers took their biggest lead, 30-20, thanks to a 3-pointer from Goodin that was part of a 10-point burst.

Xavier broke a tie by going on an 8-0 run to move ahead 21-13 with 10:23 left in the half.

NOTES: Xavier out-rebound St. John's 45-26 and 17-6 on the offensive glass. ... The Red Storm were 5 of 23 from long distance. They entered the game third in the Big East in made 3-pointers. ... St. John's leads the Big East in blocked shots. The Red Storm blocked five shots against Xavier, giving them 144 for the season. ... Xavier G Trevon Bluiett's 40 points against Cincinnati on Jan. 26 were the most for the Musketeers since David West scored 47 in 2003. Bluiett moved into 23d place in Xavier's all-time scoring list with 1,308 points. ... Xavier won the 1958 NIT Championship at Madison Square Garden.