The Celtics  live to fight another day.
Jason Terry  nailed a go-ahead three with 90 seconds left in overtime and scored Boston’s final seven points as the Celtics overcame blowing a 20-point third-quarter lead and beat the Knicks, 97-90, in Game 4 Sunday afternoon at TD Garden. With the win, the Celtics stave off elimination and will play the Knicks in Game 5 Wednesday night at Madison Square Garden, trailing the series, 3-1.
In a season filled with a record 11 overtime games, Game 4 appropriately came down to an extra period.
Paul Pierce  scored 29, Jeff Green  added 26 and Kevin Garnett  chipped in with 13 points and 17 rebounds for the Celtics, who blew a 20-point third quarter lead. Carmelo Anthony had 36 points while Raymond Felton  added 27 for New York, which was playing without the suspended J.R. Smith.
For the third time in the series, the Celtics took a halftime lead but this time Celtics were overpowering in building their advantage. The Celtics shot 50 percent in the first quarter, as Pierce led the way with seven points and the Celtics led, 22-17 after one.
Pierce led the charge against the Knicks in the second quarter, scoring 10 of his 17 first-half points. Led by a pair of Pierce threes late, Boston went on a 19-6 run to end the second quarter and grabbed a 54-35 halftime lead. The Knicks were extremely sloppy in the first half, committing 13 turnovers.
Green was also huge in the second quarter, scoring nine of his 15 first-half points and helping Boston outscore New York, 32-18. It took four games but the Celtics produced their best half of offensive basketball, making 20-of-39 shots (51.3 percent).
Fouls became a huge issue in the third quarter.
Garnett, Green all picked up their fourth fouls in the first four minutes. The Knicks were in the bonus with 7:12 left in the third quarter. Still, the Celtics managed a 20-point lead at 59-39. But the Knicks – led by Raymond Felton – finally got hot from 3-point range.
Carmelo Anthony’s jumper with 6:44 left in the third capped an 8-0 Knicks run and cut the lead to 12, 59-47. After a Green layup, the Knicks collected a loose ball rebound and Raymond Felton drilled a three, cutting Boston’s lead to 11, 61-50.
Anthony was called for his fourth foul moments later and the Celtics regained momentum, building the lead back to 14. But Felton hit his third three with three minutes left in the quarter to pare the lead down to 10, 65-55. Anthony came out of the game with 3:35 left in the third and the Knicks down, 14. Without their MVP, Felton and Iman Shumpert led the Knicks on a 14-3 surge to end the third quarter, including a three with 0.2 seconds left in quarter as Boston led by just three, 68-65, heading into the final quarter. Terry hit another jumper with 50.4 second left to re-establish the three-point lead, 93-90.
After a Garnett free throw on an illegal defense call, Anthony hit a layup to cut the Boston lead to two. Pierce answered with a deep three with 9:40 left to put Boston up, 72-67. An Iman Shumpert steal of Pierce and layup with 7:16 left tied the game, 74-74.
With 4:49 left, Jeff Green’s layup put Boston up, 80-76, marking the first time in the series the Celtics reached the 80-point plateau. Moments later, Bass fouled out with 4:27 left.
Shumpert drilled a three with 4:02 left and Boston’s lead was down to two, 82-80. Anthony’s layup with 3:36 remaining tied the game, 82-82. After a Celtics turnover on Garnett, Anthony’s three rimmed in and out with three minutes left. Green fired up a desperation three as the shot clock expired setting up another Anthony attempt. Jason Kidd  tapped the loose ball rebound to a teammate and the Knicks called timeout.
Green picked up his fifth foul with 1:50 left but Anthony missed both free throws. Green missed a wild shot on the next possession and Felton came down and hit a jumper with 1:18 left to give New York its first lead, 84-82. Garnett tied it with a jumper with 1:07 left. Anthony missed a jumper as the shot clock expired and Pierce grabbed the rebound with 18 seconds left to give the Celtics the chance to win in regulation. Pierce went to an iso play and missed a three with 0.4 seconds left, giving New York a chance at a desperation play from mid-court. Wilcox batted the inbounds pass out of bounds to force OT.
As the shot clock was expiring, Garnett hit a baseline jumper with a 2:43 left in OT to put Boston up, 88-86. But Anthony came back down, drew a foul and hit two free throws with 2:22 left to tie the game again.
Terry’s pull-up three with 1:32 left put Boston up, 91-88. Anthony responded with a jumper to cut the lead to one, 91-90. Anthony picked up his fifth foul with 1:01 left in overtime. Anthony missed a three with 27 seconds left and Terry hit both free throws to put Boston up, 95-90, and send the series back to New York for Wednesday night.
For complete coverage from Mike Petraglia and Ben Rohrbach from the Garden, visit the Celtics team page at weei.com/celtics.