Game 2 of the best-of-7 series is here Sunday (7:30 p.m. ET; NBCSN, SN360, TVAS2, NBCSWA, FS-O).
Panarin, whose 82 points in the regular season set a Columbus single-season record, had a goal and two assists. He was acquired in a trade from the Chicago Blackhawks on June 23, 2017.
"We traded away a really good player in [Brandon Saad] to get him," Columbus coach John Tortorella said. "A different type of player, a guy that makes something out of nothing. Makes a great play on the tying goal and scores just a goal that a lot of people can't score in this league. That's sometimes the difference between winning and losing."
Kuznetsov scored twice during a five-minute power play after Josh Anderson received a major penalty for boarding and a game misconduct at 17:23 of the first period for his hit on Capitals defenseman Michal Kempny, who left the game with an upper-body injury.
Kuznetsov gave Washington a 1-0 lead at 17:52. Tortorella challenged for goaltender interference by T.J. Oshie, but the goal was upheld after video review.
Kuznetsov scored again 29 seconds later, beating Bobrovsky from the left face-off circle at 18:21 to make it 2-0.
"You've got a lead there, you've got to be smart," Grubauer said. "It doesn't matter what it is. Whatever you do, protect the middle of the ice. Don't make it hard on yourself, basically. We kind of shot ourselves in the foot a little bit again."
Wennberg cut the Capitals lead to 2-1 when he scored at 4:48 of the second period off a cross-ice pass from Boone Jenner.