Cirelli gave the Lightning a 1-0 lead at 4:09 of the first period, burying the rebound of Brandon Hagel's sharp-angled shot in the low slot.
Dadonov tied it 1-1 at 6:05 when Ilya Lyubushkin's one-timer from the point deflected in off his skate near the left post.
Cirelli put the Lightning back in front 2-1 at 8:34. He got the rebound of his own redirection in the low slot, spun and tucked a shot past the right pad of Oettinger.
“They defended well, and maybe that's on us by not getting enough pucks to the net and some scrambles there to kind of break that down,” Cirelli said. “I thought we were better tonight (than Thursday), but still not good enough. It’s on us to be able to go out there and do what we’ve got to do for the full 60."
Heiskanen tied it 2-2 at 15:49 of the first, taking a cross-ice pass from Duchene and scoring with a wrist shot from the left circle that beat Vasilevskiy glove side.
“We’ve won a lot of games when we’re tied going into the third,” Oettinger said. “Guys needed to step up and make big plays, and we had a few of those.”
NOTES: Cirelli extended his goal streak to five games (six goals). ... Duchene has eight points (four goals, four assists) in his past six games.