Colin Greening scored 7:39 into double overtime, and the Ottawa Senators rallied for a 2-1 victory over the Pittsburgh Penguins that cut their series deficit to 2-1 on Sunday night.
Daniel Alfredsson got Ottawa even 1-1 by scoring a short-handed goal with 29 seconds left in regulation just after the Senators pulled goalie Craig Anderson for an extra skater.
Anderson made 49 saves, including 18 after regulation. Tomas Vokoun stopped 46 shots for Pittsburgh and took his first loss (4-1) since taking over for No. 1 Penguins goalie Marc-Andre Fleury.
Game 4 of the Eastern Conference semifinal series will be in Ottawa on Wednesday.
Tyler Kennedy scored with just over a minute to play in the second period to give the Penguins a 1-0 lead. That goal stood up until Alfredsson tied it in the closing seconds of the third.