Carkner fired a slap shot through traffic that deflected off the Penguins' Matt Cooke from the right point for his first goal of the postseason, ending the longest game this NHL playoff season.
Peter Regin tied it with 9:36 to play, Mike Fisher and Jarkko Ruutu also scored, and Jason Spezza and Erik Karlsson each had two assists for the Senators, who have won two of three at Mellon Arena.
Sidney Crosby had a goal and an assist to give him multiple points in every postseason game this season, and Kris Letang and Chris Kunitz also scored for Pittsburgh.
Flyers 3 Devils 0: In Newark, N.J., the Philadelphia Flyers were the last team into the Stanley Cup playoffs, but are the first to reach the second round.
Flyers goalie Brian Boucher stopped 27 shots for his second career playoff shutout to help Philadelphia finish off the series in Game 5.
Claude Giroux scored twice in the second period after Danny Briere had given the Flyers a 1-0 lead in the first. Boucher made the offense stand up as Philadelphia beat New Jersey for the ninth time in 11 meetings this season.
Blackhawks 3 Predators 0: In Nashville, Tenn., Patrick Sharp scored his first two goals of the postseason and Chicago finally found its offensive form to tie the series at 2-2.
Jonathan Toews also scored his first playoff goal and had an assist. Marian Hossa had an assist, just his second in the series, and rookie Antti Niemi stopped 33 shots for his second shutout.
The Blackhawks made a couple lineup changes, including playing defenseman Brian Campbell for the first time since he broke his collarbone and a rib March 14.
Nashville lost its first Game 4 in three tries on home-ice. The Predators gave no offensive support to goalie Pekka Rinne, who had allowed only two even-strength goals the first three games.
Sharks 5 Avalanche 0: In San Jose, Calif., Evgeni Nabokov stopped 28 shots to record his seventh career playoff shutout, Logan Couture scored twice and San Jose took a 3-2 lead in the first-round series.
Joe Pavelski, Patrick Marleau and Dwight Helminen also scored for the Sharks.
Colorado goalie Craig Anderson stopped 29 on 33 shots before being replaced by Peter Budaj at 11:05 of the third period.
Tempers flared as San Jose scored three times in the second period in the biggest offensive outburst by either team in the first round.
Neither team had held a lead of more than one goal until the Sharks took a 2-0 lead.
