Benn produced all of his points in the first period. The left winger opened the scoring 40 seconds in, redirecting a shot by Alex Goligoski from along the right boards into the left side of the net. He struck again at the 5:37 mark, snapping a shot past Bishop from the right circle.
Two minutes later, Lightning defenseman Radko Gudas was dealt a match penalty for an illegal check to Roussel's head. Dallas failed to capitalize on the five-minute major, but Benn and his brother Jordie set up Seguin late in the period to make it 3-0.
Tampa Bay responded with a pair of goals early in the second period. Stamkos scored two minutes in, and Sustr lifted a rebound past Lehtonen at 6:44 for his first NHL goal.
Fiddler and Roussel beat Bishop with backhanders in the third to secure the victory that lifted Dallas past Phoenix into the second wild-card position in the Western Conference. The Stars last reached the postseason in 2008.
NOTES: Sustr was recalled from the AHL on Friday. . Tampa Bay D Mike Kostka missed his second game with a concussion that resulted in a three-game league suspension for Montreal D Douglas Murray. . Dallas LW Erik Cole (upper body) returned after being sidelined seven games. Stars LW Ray Whitney (lower body) sat out for the first time since Jan. 2. . During a pregame ceremony on the plaza, the Lightning unveiled a bronze statue depicting former captain Dave Andreychuk raising the 2004 Stanley Cup.