More reaction from outside Madison Square Garden:

Jayson Tatum will have an MRI on Tuesday after suffering a non-contact injury, Celtics coach Joe Mazzulla told reporters after the Knicks took Game 4 over Boston.

Tatum grabbed at his right ankle and didn't put any weight on his right leg as he left the court. ESPN's broadcast showed him in a wheelchair in a back hallway at MSG. There was no other update on his status.

With the Celtics facing elimination, losing Tatum for Game 5 (and potentially beyond) would be a disastrous blow.

The first videos have started to pour in from outside Madison Square Garden. Enjoy.

The Knicks' head coach is embracing his team's never-say-die ethos.

"You just gotta keep fighting," Tom Thibodeau told reporters after his team's 14-point comeback to take Game 4 over the Celtics -- the Knicks' third double-digit comeback in as many wins this series.

"It starts with your defense," Thibodeau said. "Then you gotta have toughness. Then you gotta do it together."

After Jalen Brunson's 39-point Game 4, the Knicks' leading man said his team has "one more" after going up 3-1 over the Celtics.

"Just found a way to make plays and get us going," Brunson told ESPN's Lisa Salters. "And we got one more."

Brunson praised teammates Mikal Bridges, Karl-Anthony Towns and OG Anunoby, all of whom finished with over 20 points on Monday.

"They played phenomenal," Brunson said. "Didn't quit, kept fighting and that's most important. Whenever you get in a. hole, can't quit. I think you saw that."

Game 5 is in Boston on Wednesday and the Knicks can make their first Eastern Conference Final since 2000.

"Gotta focus," Brunson said. "Great place to play, great environment. We gotta focus. That's a great team over there."

The Knicks overturned a 14-point deficit to beat the Celtics 121-113 in Game 4 at Madison Square Garden.

The win gives New York a 3-1 lead in the series as it heads back to Boston for Game 5. Perhaps just as important, Jayson Tatum left the game in the final minutes after suffering an apparent non-contact injury. Tatum, who had 42 points to lead the Celtics, left the court without putting any weight on his right leg and was shown on ESPN's broadcast in a wheelchair.

Jalen Brunson's 39 points led the Knicks, including 18 during a huge third quarter as the Knicks were coming back. Mikal Bridges finished with 23 and was excellent during the fourth quarter as the Knicks took the lead and held it.

It wasn't quite as dramatic as the Knicks' first two wins of this series but again, their resilience was very much on display as they stunned the Celtics in another game Boston led throughout the early goings.

The Knicks can secure their first Eastern Conference Finals berth since 2000 in Boston on Wednesday night.

Jayson Tatum is getting attention on the court and looks to be in real pain. It's not entirely clear what happened, but Tatum was holding his ankle.

He left the floor with help and did not put any weight on his right leg.. The replay looked like a non-contact injury.

Obviously any injury would have massive ramifications on the series.

The Knicks, yet again, are showing what they're made of in crunch-time.

Mikal Bridges in particular has been sublime -- he hasn't missed a shot in the fourth quarter -- and the Celtics are suddenly on their heels with 3:21 to go in the game.

The Knicks have completely turned this game on its head in the second half, but they still need to hang on.

Jayson Tatum can't miss right now. Neither can Mikal Bridges.

It's become a wildly entertaining fourth quarter here, and Tatum -- who now has 39 points -- is keeping the Celtics in it right now. The Knicks are doing a good job of forcing him into tough shots, but he's making them anyway.

Brunson has been quiet so far in the fourth but as we come up on crunch time, he could be the person on whom this game hinges.

A tough turn of events for the Knicks, who lose their challenge with over 10 minutes to go in the game and now need to sit Josh Hart with five fouls.

A potentially consequential moment here as Tom Thibodeau uses his challenge after Josh Hart was called for a blocking foul. If upheld, it would be Hart's fifth foul on the night.

Knicks still lead 92-89.

A resurgent third quarter led by 18 points from Jalen Brunson helped the Knicks overturn a 14-point deficit to lead by three entering the final 12 minutes.

Madison Square Garden erupted as OG Anunoby gave the Knicks their first lead since early in the game on a 3-pointer to make it 86-85. Josh Hart then extended it to three with a couple seconds to go before the buzzer.

The Knicks are 12 minutes away from taking what would look like a decisive 3-1 lead in the series.