Alex Killorn scored the tiebreaker with about 8 minutes left, Andrei Vasilevskiy made 36 saves, and the Tampa Bay Lightning beat the Washington Capitals 4-2, to tie the Eastern Conference final at two games apiece.
Killorn was left pretty much alone during a defensive breakdown by Washington and scored 6 seconds after a Tampa Bay power play expired, putting in a pass from Ondrej Palat.
Steven Stamkos and Brayden Point scored Tampa Bay's first two goals, and Anthony Cirelli added an empty-netter with a second left.
Washington's goals came from Evgeny Kuznetsov off an assist by Alex Ovechkin and defenceman Dmitry Orlov.
The Lightning host Game 5 on Saturday night, with Game 6 back in Washington on Monday.
The road team has won every game in the series so far.