Dadonov made it 2-0 at 3:05 of the third period, scoring glove side from the high slot after he exited the penalty box.
"Just tried to hide it as much as possible, just use the bodies as a screen, just get a puck through," Dadonov said.
Klingberg cut it to 2-1 at 5:58 with a quick shot from the top of the right circle.
"I think we had our looks," Klingberg said. "Obviously, at 5-on-5 we had a few breakaways, 2-on-1s, but I think [the power play] didn't really click today. We were a little scrambly on the outside and in gaining entrance that easy, so that's something we'll look at and see if we can do a better job next game."
Seguin pushed it 3-1 at 16:29, scoring his second power-play goal from the low slot off a pass from Jamie Benn.
"Obviously, we capitalized when we needed to, and we're happy with a couple tonight," Seguin said.