The Lightning, who had gone 0-for-14 on the power play over their past four games, got two goals with the man advantage in Game Two of a best-of-seven championship series being held in Edmonton to limit travel and minimize COVID-19 risk.
Three first-period goals over a four-minute span, including power-play tallies from Brayden Point and Ondrej Palat, put Tampa Bay in control early. Kevin Shattenkirk's goal made it 3-0.
Dallas finally got on the board with five minutes left in the second period when Joe Pavelski tipped in a shot from John Klingberg five seconds after Palat was serving a two-minute slashing penalty.
The Stars pulled to within a goal when Mattias Janmark scored his first of the playoffs early in the third period but the Lightning, who have not lost two consecutive games all postseason, held firm. (Reporting by Frank Pingue in Toronto; Editing by Peter Rutherford )