Looking to push the defending title winners to the brink of elimination in the Eastern Conference finals, the Ottawa Senators clawed back from down 3-0 to threaten late in Friday night's Game 4 against the Pittsburgh Penguins.

Thankfully for Steel City fans, however, the Pens clung to a lead on a night their offense decided to come alive, and it was Pittsburgh that took the latest entry in the Eastern back-and-forth, a 3-2 victory that evened the conference finals at 2-2.

Erik Karlsson just about lifted the Sens to an improbable comeback with his assist on a late-third goal from Tom Pyatt, a score that cut the Pens' lead to one, but Ottawa could not capitalize on a last-minute too-many-men-on-the-ice blunder from the visitors.

The Pens, meanwhile, did exactly what they needed to do to regain momentum Friday, and it had little to do with their headlining goalie swap of Marc-Andre Fleury for Matt Murray.

After three straight one-goal games, including a Game 3 that looked a lot like their deflating Game 6 loss to the Washington Capitals in the second round of the postseason, Pittsburgh got out in space, pushed the puck deep into Ottawa's typically stout defense and finally showcased its talent with a 3-0 lead by the second period on Friday night.

Sidney Crosby, who was virtually missing in action during the Pens' 5-1 loss two days earlier, was especially active, shrugging off a penalized headlock from Jean-Gabriel Pageau and setting up shop in front of Craig Anderson for a perfectly executed score that put Pittsburgh up 2-0.

And the Pens defense, still without injured regulars, had its own fair share of contributions, including an Olli Maatta goal that got the defending Stanley Cup champions back on the right foot late in the first.

Ottawa came out in the third with a little more pep than the Pens, and that at least partially explains the Sens' climb back into contention. But Murray mostly stood his ground even when Pittsburgh's blue line let up in the final period of action, allowing the second Sens goal only after the puck slipped through teammates' legs and from out of his sight.

It was fitting, perhaps, that Ottawa's comeback hopes ended on a failed power-play try, as extra-man advantages hardly gave the Sens an edge over the course of Friday's contest -- an all-too-familiar problem for Guy Boucher's defensively minded underdogs. The Sens went 0-for-4 on power plays in Game 4, and they'll need to ensure they get back to disrupting the Pens' space on offense in Game 5 if they intend to win their way and reclaim a series lead.