Then with just 3.5 seconds left, Filppula shoveled in the equalizer during a scrum in front the Islanders' net.
He also scored in the shootout, which was decided by Nikita Kucherov's goal in the second round.
Ben Bishop made 32 saves for Tampa Bay.
Nielsen and Kyle Okposo scored for the Islanders, who lost for the 13th time in 14 games.
Nabokov finished with 34 saves.
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