Will Smith had a goal and an assist for the Sharks (14-29-6), who have lost three in a row and six of seven. Yaroslav Askarov made 27 saves.
“For the majority of the game I liked our game,” San Jose coach Ryan Warsofsky said. “We just got real immature in the third period … just a young team that got scrambly. [They] put us on our heels, and we couldn’t relieve the pressure by making some plays.”
Vinni Lettieri gave Boston a 1-0 lead at 9:21 of the first period on a redirection of Jordan Oesterle’s shot from the right point. It was his second goal in as many games.
“Both goals are direct result of being around the front of the net,” Bruins coach Joe Sacco said. “To score in this league you have to be on the inside, and that’s what he does.”
San Jose tied it at 1-1 when Barclay Goodrow scored at 13:16. Nico Sturm outraced Andrew Peeke to a loose puck behind the Bruins net and made a quick pass to Goodrow, who beat Korpisalo to the high blocker with a shot from the slot.
Pastrnak was credited with a goal for a 2-1 Bruins lead at 7:01 of the second period after his shot ricochetted off the skate of Sharks defenseman Jake Walman and snuck past Askarov.
Smith, a Boston native and former Boston College standout, tied it 2-2 at 8:52. He intercepted a pass in the neutral zone, connected with Mikael Granlund on a give-and-go and beat Korpisalo to the short side from the right face-off circle.
“It was pretty amazing,” Smith said of playing in his hometown. “I’ve come to plenty of games here, so it was a dream come true.
“I wanted to be ready to go. I had a lot of people in the building, and this game was for all of them too. I wouldn’t be here without them.”