San Jose killed off five penalties totaling 9:11 in power-play time, including a 5-on-3 for 46 seconds when both Devin Setoguchi and Dan Boyle were in the box early in the second period. A goal there would have lifted Boston's lead to 3-1.
"It's been pretty successful all year," Boyle said of the PK, which is perfect in six of San Jose's last seven games and is now operating at an 85.8-percent success rate. "(Tuesday), the PK was probably a big reason we won the game."
It could also be argued that the Bruins' power play is why they lost the game. Choose your side, of course, but Boston is now two for its last 30 with the advantage in the last six games after scoring 10 power-play goals in its previous seven games.
"I guess we didn't put the work boots on in the power play," Bruins center Marc Savard said. "We needed to do that. We talked about that. That was our game plan going in. We were going to have to work and get on pucks and I think we didn't win the battles on the power play. We have to get back to winning them."
Thornton said the Sharks were letting goalie Evgeni Nabokov see the puck, which was a big difference in their success on the PK. Nabokov made eight saves on the PK.
"We were trying to clear the front of the net and let him see the puck," Thornton said.
It wasn't just how many penalties the Sharks killed, it was when. The 5-on-3 was obviously big, but San Jose had to kill two more after Thornton scored to make it 4-2 halfway through the third period.
Jonathan Cheechoo was called for hooking at 10:55 of the third and Boyle went off for holding at 15:36. The Bruins generated nothing.
"I don't think we're moving the puck with enough authority," Bruins coach Claude Julien said. "We're not moving around quick enough and definitely not strong enough on the puck. Those three things aren't happening right now so our power play is certainly not helping us right now."
Contact Dan Rosen at firstname.lastname@example.org