Clarke MacArthur scored a power-play goal with 6:30 gone in the first overtime and the Ottawa Senators beat the Boston Bruins 3-2 on Sunday to win their first-round playoff series in six games.
Craig Anderson stopped 28 shots for Ottawa, which advanced in the postseason for the first time since 2013. It was the fourth overtime game in the series.
Tuukka Rask made 26 saves for the Bruins, and Boston got goals from Drew Stafford and Patrice Bergeron.
Bobby Ryan and Kyle Turris also scored for Ottawa.