Seidenberg/By S. Bradley

BOSTON — Tampa Bay goaltender Mike Smith got caught cheating and Bruins defenseman Dennis Seidenberg exacted the punishment on him tonight at TD Garden.

Seidenberg fired a shot from between the red line and blue line near the side wall into an empty net with just 20 seconds left in the first period after Smith left the crease in anticipation of a dump-in along the boards.

It was Seidenberg’s first goal of the season.

“I mean, I tried to sell it a little bit,” said the blueliner. “I mean, I tried to sell the rim and he went for it obviously. So it wasn’t too hard though.”

Seidenberg said he had only seen that play work once before — when Carolina’s Cory Stillman beat Florida’s Tomas Vokoun. The second time was a charm for the Bruins, who went up 2-0 en route to an 8-1 rout. Later in the game, Smith misplayed a puck that resulted in a goal by Shawn Thornton. Bruins head coach Claude Julien was grateful for Seidenberg’s trickery.

“I think it was a bigger goal than maybe a lot of people will think for numerous reasons,” said the coach. “No. 1, it gave us that two-goal cushion. The other part is, Smith is a really good puck-handler. By scoring that goal catching him cheating, now you’re putting doubts in his mind about whether he wants to come out or not. So maybe we took a part of his game away from him. And then that other goal that Thornton scored off a miscue obviously at that point, he probably really lost his concentration and I think we had gotten to him by that time.”