A Capitals-Penguins series is a dream matchup for the NHL, and Game 3 of the teams' second round battle was, in so many ways, a showcase for the sport at its best. On Monday night we saw clutch goals, physical play, great goaltending, an amped up crowd and a wild, late rally. We saw a little desperation and a lot of nerves. And we also saw an overtime result -- a 3-2 Washington victory -- that kept the series from turning into a laugher.

But Game 3 was also no laughing matter. It's hard to imagine a worse visual than Sidney Crosby, with the entire hockey world watching, being helped off the ice during a playoff game with what appeared to be a head injury. Anything that happens to Crosby - the best player in the world, who's been especially deserving of that title this spring - is bad news for the NHL, a league that tries so hard to promote its stars. But this particular injury, given Crosby's history of concussions, is so much worse.

The Matt Niskanen cross-check that ended his night wasn't especially reckless: Crosby was falling toward the ice, and in a split-second reaction, Niskanen plowed into him with his stick. The outcome, though, was no less scary. After the game, Pittsburgh coach Mike Sullivan didn't provide an update about Crosby's health, but Pens fans will have no trouble coming up with doomsday scenarios in the absence of any information. (During his mid-game interview, Sullivan did refer to Crosby getting hit in the head, though he didn't give any indication about the severity of the injury.)

This series was hardly lacking for storylines entering Game 3: It features the league's two best teams, and its two most recognizable stars. The Penguins are looking to repeat as champions, while the Caps are looking to avoid yet another premature exit. And there's a compelling cast of characters: Marc-Andre Fleury stepping into a familiar but unexpected role, Kevin Shattenkirk looking to prove he really is the final piece to Washington's puzzle, Braden Holtby hoping to bounce back from an ugly Game 2, plus stars like Alex Ovechkin, Phil Kessel and Evgeni Malkin. (This series even had a dumb controversy, for good measure.)

But Crosby's injury is the story of this series now. If he misses any time, the already-banged-up Penguins will have to adapt, with even more responsibility falling to Malkin. The Caps, meanwhile, could have an opportunity to take advantage of a Pens team missing its best forward in Crosby, its best defenseman in Kris Letang, and its best goalie in Matt Murray.

It's not accurate to call Crosby's injury a turning point in Game 3: It happened early in the first period, and the momentum would shift multiple times as the night went on. Washington took a first-period lead, then Pittsburgh appeared to tie the score in the second period on a goal that was first upheld by replay, then overturned by it. Evgeny Kuznetsov extended the Caps lead to 2-0 with a third period goal, displaying remarkable patience to beat a sprawling Fleury. But the Pens would score twice in the final two minutes of regulation to tie the game and send the Pittsburgh crowd into a frenzy. The night had one final twist: a Shattenkirk power-play goal to give Washington a badly needed win and a fighting chance in the series.

But the series has a different feel now, even if Washington still trails by a game, and even though the Caps are still weighed down by the usual postseason baggage. Pittsburgh appeared to be cruising through the Eastern Conference playoffs, but the dynamic of the series changes without Crosby in the lineup. Pittsburgh suddenly looks a little less invincible than it did Monday morning.