"It was a good effort by everyone and a good road game for us," Clemmensen said. "We had a game plan and we stuck with it. This team is playing with a lot of confidence right now.
"We went down in the first but we stuck to it and believed in the game plan, and that's probably the biggest difference between now and the beginning of the year."
The Panthers won just three of their first 16 games and it cost coach Kevin Dineen his job. Peter Horachek took over and sustained a 3-2 loss at Ottawa on Nov. 9.
That marked the last time the Senators have won consecutive games.
"At that point I was just opening the doors," Horachek said. "I was just telling them how I feel the team should play, and I think they wanted to play hard with a new coach. The structure and the confidence wasn't there, and now the guys know they are capable of winning in whatever building they are in.
"We have to play our game and not bend around and see how other teams are going to play."
"We just didn't do enough to win. We got too passive and found a way to lose," Spezza said. "It's clear we're feeling pressure now and we're feeling the heat. We're trying to win hockey games, and the effort is there, but we don't execute.
"We don't play loose enough with the puck and we're making mistakes at the end. That's the position we've got ourselves in and we have to find a way to get out because no one is going to give us any help."
Both teams took turns taking and giving away the lead through the first two periods, starting with the Panthers.
Hayes opened the scoring with his fourth goal when he beat Anderson from the right hash mark at 5:39 of the first period.
After a review to see if the puck was kicked in, Neil was credited with the tying goal at 9:17 of the period. Clarke MacArthur took the original shot, but after Clemmensen made the save, the puck bounced in of Neil's skate for his fifth goal.
The Senators took the lead in the final minute of the period when Spezza made a sensational play, first getting the puck around Panthers defenseman Dylan Olsen at the faceoff circle and then beating Clemmensen high and on the short side with very little space.
It was Spezza's 11th goal of the season and first in 13 games.
Barkov tied it for the Panthers at 17:11 of the second period with his sixth of the season. He redirected Gilbert's shot past Anderson.
The Senators were also forced to play the final two periods without forward Mika Zibanejad who left after only five shifts and 2:38 of ice time because of an upper-body injury.
Defensemen Patrick Wiercioch and Eric Cryba, along with forward Cory Conacher, sat out for the Senators. Defenseman Mike Mottau and forward Scott Gomez were scratched by the Panthers. ... The Senators have allowed an NHL-high 42 first-period goals. Entering play Thursday, Ottawa had the most penalty minutes in the league with 164. The Senators were 24th with a 78.9 percent efficiency on the penalty kill.
Copyright by STATS LLC and The Associated Press
OTTAWA, ON - DECEMBER 19: Milan Michalek #9 of the Ottawa Senators balances a puck on his stick during warmup...