WASHINGTON -- The Maple Leafs didn't let another opportunity get away in Game 2.

Kasperi Kapanen scored two goals, including the winner 12 minutes into double overtime as Toronto evened up its best-of-seven series with Washington at a game apiece with a 4-3 victory on Saturday night.

Morgan Rielly and James van Riemsdyk also potted goals while Frederik Andersen stood tall again with 47 saves in a game that also saw Roman Polak exit with injury. Jake Gardiner and Rielly both played over 40 minutes in his absence.

The Leafs led 3-2 with just over seven minutes left in regulation when Nicklas Backstrom tied it 3-3 for the Capitals. The club also had a 2-0 first-period lead slip away two nights earlier in a Game 1 overtime defeat. They ultimately rallied for their first post-season victory since May 12, 2013.

Alex Ovechkin and John Carlson managed power-play goals for Washington and Braden Holtby gave up four goals on 51 shots.

The Leafs will be feeling plenty confident when they host Game 3 at the Air Canada Centre on Monday night. Doubt will likely be on the minds of the Caps given their Stanley Cup aspirations this spring and years of playoff disappointment.

Fast-starters in Game 1, it was the Leafs who were under siege early in Game 2. Washington looked like the Presidents' Trophy winners -- puck-hungry, physical and continually on the attack. The Caps held the Leafs without a shot for the first 11 minutes, buoyed by a charged crowd, which was given small red cowbells before the game.

It was more persistent possession of the puck in the Toronto end than scoring chances galore for the hometown Caps, even after a power play 21 seconds in. Andersen still needed to come up big though, stopping a dangerous Lars Eller attempt and then denying Brett Connolly, with maybe his best save of the period, on a partial breakaway.

The 27-year-old, who was mostly sharp if still error-prone in Game 1 (three goals, 44 shots), managed to keep the Leafs in front until they gained some momentum and scored the first goal. Van Riemsdyk got it with two and a half minutes to go in the first, the beneficiary of some strong puck work by Gardiner.

Almost half the first frame was special teams play with six minors called, including embellishment on Ovechkin, who finished with nine shots.

It was the Capitals captain who evened the score with the first of two power-play goals for Washington less than four minutes into the second. T.J. Oshie came up with a loose puck in the left corner -- three Leafs there battling for it -- and fed it out to Ovechkin, who quickly fired between the pads of Andersen.

Martin Marincin was in the box for whacking Eller in retaliation for a shove to the face.

The Leafs had a strong push after the goal, but it was the Caps who struck next on a blue-line blast from Carlson with Washington on another power play -- this one with Connor Carrick in the box for an apparent high-stick.

A short while later a scary collision with Brooks Orpik knocked Polak from the game. The 30-year-old banged legs with Orpik and landed awkwardly on his right leg. He yelped in pain and had to be helped off the ice and into the dressing room.

Toronto was already playing without top minute-eater Nikita Zaitsev, who could be back for Game 3.

Undeterred, Kapanen evened it up at two on the shift after Polak's injury. The Leafs then took back the lead with on a power play of their own with 13 seconds left in the second as Rielly fired a seeing-eye shot through traffic.

As was evident in the opener, the Leafs -- nine of whom were playing in their first NHL post-season -- seemed comfortable in the intense playoff terrain, even against a heavily favoured opponent loaded with experience.

The whirlwind second period ultimately concluded with four goals, four minor penalties, one injured defenceman and plenty of jeering between the Leafs and Caps.

Remaining quiet to that point following a pointless playoff debut in Game 1 was Auston Matthews. Prior to the game Leafs coach Mike Babcock advised that Matthews just remain patient, "keep doing the right things and don't deviate."

Matthews came on as the game evolved and finished with four shots and 10 attempts, his line the Leafs best in terms of possession.

The Leafs were holding their own with the 3-2 lead until they got pinned in their end for upwards of minute during the back half of the third. After Gardiner's clearing attempt failed to get out, Dmitry Orlov sent a point pass to Backstrom. Gardiner got a stick on it, but not enough as the Swedish centre tucked it in to tie it up at 3-3.

Toronto dropped 10 games when leading after two periods during the regular season (31-1-9).

Andersen had to make a number of big saves in the waning moments of regulation as the Leafs just hung on for overtime. The Capitals had 31 even-strength shot attempts in the third period.

Both teams came up empty in a spirited first overtime, Ovechkin even denied on a breakaway with 27 seconds left. The Leafs were rotating four defencemen for most of the extra time with Marincin and Matt Hunwick also both logging heavy ice-time.