The Ottawa Senators drew first blood against Stanley Cup champions the Pittsburgh Penguins in their Eastern Conference final opener.
Overtime was needed in Pittsburgh as the Senators prevailed 2-1 away from home on Saturday.
Bobby Ryan was the game-one hero at PPG Paints Arena, settling the contest five minutes into OT.
Ryan moved past Olli Maatta before firing a shot beyond Penguins goalie Marc-Andre Fleury.
The Penguins had restored parity with less than six minutes remaining in the third period, when Evgeni Malkin - who leads the NHL with 19 playoff points - tipped the puck through Craig Anderson's legs.
Earlier, Jean-Gabriel Pageau gave the Senators a 1-0 lead 14:32 into the opening period.
Game two of the best-of-seven series is on Monday.