Tom Poti, Eric Fehr and Mike Green also scored for the Capitals, who have won three games in a row. Making his fourth straight start for Washington, Brent Johnson, who was honored as the NHL's third star for the week ending Nov. 9, stopped 34-of-36 shots.
Gary Roberts had a pair of power-play goals for Tampa Bay, which has lost three of its last four games.
Olaf Kolzig, who spent 16 seasons with the Capitals before signing with the Lightning as a free agent July 1, gave up four goals on 30 shots in defeat.
Exploding whale video goes viral on Internet
Texas principal bans speaking Spanish, stirs controversy