Evgeni Dadonov also scored and Michal Repik had two assists for Florida (3-3).
Clemmensen, signed as a free agent in the offseason as the backup to Tomas Vokoun, smothered a point-blank shot by Dallas rookie Jamie Benn 25 seconds into the final period.
Benn ended Clemmensen's shutout bid at 10:11 of the third period while the Stars (2-2) skated 5-on-3.
Rookie goalies Matt Climie and Brent Krahn shared the load for Dallas (2-2), which opened a stretch of three games in three nights. The teams meet again at Florida on Wednesday night.
Climie, who stopped 12 of 13 shots, was beaten by Wilson from the left circle at 11:09 of the second period. At that point, Climie was replaced by Krahn.
Kreps made it 2-0 at 14:05 of the second, converting a goal-mouth feed from Rostislav Olesz, and Dadonov tapped Jeff Taffe's centering pass by Krahn at 6:09 of the final period.
|PPG - Clay Wilson (1) Snap shot - ASST: Michal Repik (1), Kamil Kreps (1)|
1 - 0 FLA
|PPG - Kamil Kreps (1) Wrist shot - ASST: Rostislav Olesz (1), Michal Repik (2)|
2 - 0 FLA
|Evgenii Dadonov (1) Tip-in - ASST: Jeff Taffe (1), Graham Mink (1)|
3 - 0 FLA
|PPG - Jamie Benn (1) Wrist shot - ASST: Brad Richards (1), Matt Niskanen (1)|
3 - 1 FLA