Defenseman Andrei Markov and Craig Rivet scored power-play goals to help the Eastern Conference-leading Canadiens extend their winning streak to five games. Montreal, 12-3-1 overall, including nine wins by one goal, tied the third best start in franchise history with 25 points through 16 games.
Theodore was asked if his performance in the second was his best period of the season after he stopped 13 of 14 shots while Montreal managed just two shots against a rookie making his NHL debut.
"I don't know, it's up to you to decide," said Theodore, who won his fourth straight and 10th in 14 starts. "I'm just there to stop the puck. I'm just concentrating on making every save I can and from there -- we were down a goal and the guys came back to win the third period."
Tim Taylor and Vinny Prospal scored for Tampa Bay, which lost its fourth in a row. The losing streak is the defending Stanley Cup champions' longest since Dec. 9-16, 2003.
Theodore, the league's top goalie and MVP in 2002, frequently displayed his award-winning form from that season, overshadowing a solid first career start by Brian Eklund.
"The last seven or eight games I've been feeling well," Theodore said. "I've been trying to build on little details and make the little adjustments that allow me to make the big saves. I'm just concentrating on my stuff and the guys are taking care of the rest. It's fun to see them working hard like that."
The Montreal goalie stood out in the second as the Lightning held a 14-2 margin in shots, yet could only manage to beat Theodore once despite numerous scoring chances in the lopsided period.
"He made some amazing, amazing saves in the second period to keep us in the game, even though they had the lead," Koivu said. "He was a really huge part of this win tonight."
Montreal converted two of seven power-play opportunities. Tampa Bay went 0-for-8 with the man advantage.
"The key to the game was, I thought our power play was very good early, and Theodore was better," Tampa Bay coach John Tortorella said. "He made some great saves. Later on, I thought our power play struggled and you know it's going to come back and bite you, sooner or later."
Rivet, who was on the ice for both of Tampa Bay's goals, scored his second of the season 6:59 into the third to tie it at 2.
"I don't think I played my best game, so I was pretty happy to help out the team," Rivet said.
Alex Kovalev, who assisted on Rivet's goal, set up Zednik's go-ahead goal, sending his linemate in on a partial breakaway. Zednik went to his backhand, flipping a shot past Eklund to bring the sellout crowd of 21,273 out of its seats for the second time in less than three minutes.
Taylor opened the scoring 3:06 in on a play that left Theodore with little chance. Sent in on a pass by defenseman Paul Ranger, Taylor fired his first shot into Theodore before swatting the rebound up and over the goalie's glove and into the top left corner.
Eklund, a native of Braintree, Mass., who played at Brown University, made 16 saves. He stopped the first seven shots he faced before Markov beat him on a shot from the left point at 10:53.
The Montreal goalie kept up the solid effort until Prospal beat him on a deflection at 13:36 to put the Lightning ahead again at 2-1.
- The Lightning's last four-game losing streak included a 5-2 loss to the Canadiens on Dec. 13, 2003.
- Tampa Bay captain Dave Andreychuk was a healthy scratch. "I've already made that decision, he's not going to play all the games this year," Tortorella said. "We felt this is a really quick hockey team. It was a good time to get a different look."
- Montreal has sold out each of its nine games at the Bell Centre.
- Kovalev has 399 career assists.
- The 1927-28 Canadiens started 11-1-4 for 26 points, a mark matched by the 1972-73 team.