ST. PAUL, Minn. -- Alina Muller scored 18:36 into the second overtime to give Boston a 1-0 win over Minnesota on Sunday night, sending the battle for the Walter Cup as the first Professional Women's Hockey League champion to a fifth game.
The final game is Wednesday in Boston.
Theresa Schafzahl picked off a loose puck before she exited the Minnesota end, turned back to the middle of the ice and dropped a pass back to her right to Muller, who skated into the circle and beat Nicole Hensley high over her glove.
The goal came exactly a minute after a Minnesota goal was waved off because of goalie interference, bringing a cascade of boos from the record crowd of 13,104.
Taylor Heise carried the puck down the left shot and went down as she cut to the goal. The puck slipped back to Sophie Jaques, who put it in the net as Heise crashed into Boston goalie Aerin Frankel.
"After that overturned goal, I knew we were going to get it," Muller said. "Now we're going to bring it home and we're going to finish it. Unbelievable effort."
Frankel made 33 saves and Hensley had 32.
Futility on the power play continued for both teams, who entered the game without a man advantage goal on six attempts. Minnesota went 0-for-5 and is now 2-for-26 in nine playoff games. Boston went 0-for-3 and is 0-of-15 in seven playoff games.