BOSTON (CBS) -- The Stanley Cup Final is all tied up.

The St. Louis Blues rallied from a pair of one-goal deficits in the first period en route to earning a 3-2 overtime win in Game 2 on Wednesday.

Carl Gunnarsson scored the game-winning goal 3:51 into overtime, when the Blues were skating with an extra player on a delayed penalty.

Tuukka Rask made 34 saves for Boston, while Jordan Binnington stopped 21 shots for St. Louis.

The first period was a wild one, with each team scoring a pair of goals in a back-and-forth affair. Charlie Coyle opened the scoring when he one-timed a feed from Jake DeBrusk on an early power play, but St. Louis responded less than five minutes later with a Robert Bortuzzo tally from the right faceoff circle.

The Bruins regained the lead just 40 seconds later with a Joakim Nordstrom goal.

But the Blues tied the game when Vladimir Tarasenko capitalized on a Boston defensive breakdown.

That 2-2 score held through the second period.

Matt Grzelcyk suffered a head injury late in the first period after getting hit into the end boards by Oskar Sundqvist.

The two teams will get an extra day of rest, as Game 3 will be played Saturday night in St. Louis, followed by Game 4 on Monday. Game 2's results guarantee that Boston will host another game in this series, as Game 5 will be played in Boston next Thursday.