The Rangers’ Chris Kreider scored the winning goal at 7:03 of the extra period.
The Bruins had an excellent chance to close out the series but surrendered a two-goal lead and could not recover from a few mental miscues. The Bruins are 3-1 in OT this postseason and the Rangers are 1-3 in the extra period.
Boston’s power play delivered its offensive production as Nathan Horton and Torey Krug scored on the man advantage. The Bruins’ Tyler Seguin also tallied his first goal of the Stanley Cup playoffs. Boston netminder Tuukka Rask made 28 saves.
During a scoreless first period, it took the Rangers the first 6:36 before they registered a shot.
The Bruins, who entered the second period 4-for-26 on the power play during the playoffs, capitalized on the man advantage twice in the second period. First, Horton’s shot found its way through the five-hole on Lundqvist for a 1-0 lead at 4:39.
The Bruins again took advantage of the power play when Krug’s sniper-like slap shot from the point picked the top right corner for a 2-0 lead at 7:41.
With the Bruins holding a two-goal lead, MSG was a quiet building. That changed when Hagelin scored at 8:39 as the puck trickled past a sprawling Rask, who tried to recover after tripping over his own feet.
Numerous Bruins players were complaining about the ice after Game 3 and that could have been a factor as Rask appeared to catch a rut when he fell, allowing the puck to roll past him. Either way, the MSG crowd and the Rangers were given life on the goal.
But Rask remained calm and the second period ended with Boston clinging to a 2-1 lead.
Rask didn’t help his cause as the Rangers tied it at 2-2 only 1:15 into the third period. Boston’s goalie went behind the net to control the puck for defenseman Zdeno Chara, but Rask was slow in getting back into his crease and setting himself as Stepan stole the puck from Chara and scored with a wrap-around.
Seguin scored his first of the playoffs at 8:06 of the third period by not giving up on his shot. He was rewarded for his secondary effort to give the Bruins a 3-2 lead.
It didn’t last, however, as the Rangers capitalized on a Bruins too-many-men penalty when Boyle beat Rask with a shot from the slot to tie the game 3-3 at 10:00.
Kreider’s overtime tally at 7:03 forced Game 5, which will be played Saturday at 5:30 p.m. ET at TD Garden.