BOSTON - Tim Thomas stopped 33 shots after allowing another early goal, and Brad Marchand scored the game-winner to lead Boston to a 3-1 victory over the Tampa Bay Lightning on Monday night and put the Bruins one win away from the Stanley Cup Finals.

The victory gave Boston a three-games-to-two lead in the best-of-seven Eastern Conference finals, with a chance to clinch Wednesday night in Tampa Bay.

The Lightning would need to win Game 6 to force a seventh game in Boston on Friday.

Nathan Horton scored to tie it in the second period, 17 seconds after returning from the penalty box.

Marchand scored with 4 minutes, 4 seconds left in the period to give Boston a 2-1 lead.

Boston managed just 19 shots on Mike Smith as he made his first career playoff start in place of Dwayne Roloson.

Tampa Bay finally managed to pull the goalie with 42 seconds left, but Rich Peverley scored an empty-netter with 12.1 seconds left to clinch it.

The Lightning left the extra skater on the bench for the ensuing faceoff, but they couldn't come through with anything more than some shoving after the final whistle.

Thomas bounced back after allowing four straight goals in Game 4 and may have saved the season when he stopped Steve Downie with about 11 minutes left, reaching out to put his stick in front of the open net and protect a 2-1 lead.

Two nights after Tampa Bay rallied with five straight goals to overcome a 3-0 deficit and win Game 4, Boston shrugged off Simon Gagne's goal just 69 seconds in and staged a comeback of its own.

Gagne, who scored the winner in Game 4, converted a two-on-one with Steve Stamkos to beat defenseman Johnny Boychuk and put the puck past Thomas.

Thornton to play

SAN JOSE, Calif. - San Jose Sharks captain Joe Thornton is expected to play a potential elimination game in Game 5 of the Western Conference finals despite leaving the previous game with an injury.

Thornton was hurt on a shoulder-to-shoulder check by Raffi Torres in the third period of a 4-2 loss to the Vancouver Canucks on Sunday that put the Sharks in a three-games-to-one series hole.

He did not return to the game and did not take part in an optional practice Monday before the team flew to Vancouver. In other injury news, defenseman Jason Demers practiced for the first time this series and said he is ready to play.