"We know it’s going to be a fight until the end," Bruins captain Zdeno Chara said. "This is not a group that is going to give up. We’re going to fight for every point, every game. We know we can get it together like we did before."
The Oilers buzzed early and took a 1-0 lead 4:29 in when Derek Roy made a pass from behind the net to Yakupov, who beat Rask to extend his point streak to six games.
Edmonton went ahead 2-0 on the power play. With 4:07 left in the first period, Purcell sent a pass through the top of the crease to Nugent-Hopkins, who blasted in his 16th goal.
Boston got on the board with a power-play goal with 20 seconds left in the first when Eriksson tipped Dougie Hamilton’s shot past goalie Ben Scrivens, who was making his return from a hamstring injury.
The Oilers restored their two-goal lead with another power-play goal at 9:00 of the second. Purcell scored on a wrist shot through traffic from the high slot.
The Bruins made it 3-2 with 5:43 remaining in the second as Smith picked up a rebound in front of the Oilers net and whacked it past Scrivens.
Just 1:35 later, Pastrnak ticked a hard shot from the point by defenseman Chara into the Edmonton net.
There was no scoring in the third period or overtime despite a pair of glorious chances for Milan Lucic.
Both teams return to action on Friday as the Bruins play the fourth game of a five-game trip in Chicago. Edmonton will remain home to face the Minnesota Wild.
NOTES: There was speculation that recent call-up Malcolm Subban would get his first NHL start in net for the Bruins, but they opted to give Rask his 24th appearance in 25 games. … Oilers defenseman Jeff Petry (ribs) and forward Anton Lander (shoulder) left the game after the second period.