Aho made it 2-0 at 7:50 of the second period. He intercepted the puck in the defensive zone and started a 2-on-1 rush with Jordan Staal as a penalty kill expired. The Hurricanes captain then skated into the right circle before sending a pass back across to Aho, who tapped it past the outstretched right pad of Ullmark.

“That’s (Aho) to a T,” Staal said. “He reads the game so well and he understands when he can go and find openings. I was along for the ride on that one. He made a great play on my pass, and a big goal for our group.”

Batherson cut the lead to 2-1 at 10:47. Sanderson gloved down Aho’s clearing attempt at the blue line and passed down to Batherson near the left post. Batherson’s centering attempt for Claude Giroux hit off the skate of Carolina defenseman Jaccob Slavin and deflected right back to Senators forward, who quickly scored short side on Andersen.

Cozens tied it 2-2 at 16:40 of the second with a sharp-angled wrist shot from the bottom of the right circle that slipped through Andersen’s five-hole.

“Obviously, you’re going to make mistakes, everyone does,” Andersen said. “It’s about what’s next, and obviously we had to play a lot going forward.”

Ullmark pushed the game to overtime by making a crucial save with 22 seconds remaining in regulation. Ehlers sent a centering pass out front to Staal, whose one-timer from the edge of the crease was stopped by the flailing left shoulder of Ullmark.

“He’s been amazing these past two games,” Ottawa captain Brady Tkachuk said. “He kept us in it, just to have a chance.”

Andersen made a game-saving stop of his own at 11:21 of the second overtime. Michael Amadio got behind the defense and made a move in tight to his forehand, but Andersen got a piece of the shot with his glove before it hit off the crossbar.

“’Freddie’ was unbelievable,” Staal said. “It was probably one too many saves he had to make for us. It was good to see him bounce back and continue to fight for us.”

NOTES: Sanderson played a game-high 43:06. … The Hurricanes are the first team in NHL history to take a 2-0 lead in its first best-of-7 series in six straight postseasons.