OTTAWA -- The Florida Panthers are on their best roll since March 2012 as they keep on winning through a tough Canadian trip.
Tom Gilbert scored a power-play goal at 17:28 of the third period, Tomas Kopecky added a shorthanded goal at 18:19, and Florida extended its season-high winning streak to five games Thursday with a 4-2 victory against the Ottawa Senators.
Gilbert gave Florida its second lead at 3-2 when he scored his second of the season with three seconds left in a penalty to Ottawa's Jean-Gabriel Pageau. Kopecky's third made it a two-goal lead 51 seconds later after Panthers defenseman Mike Weaver was sent off for tripping at 17:45.
"It's contagious when you're winning," Gilbert said. "It's also contagious when you're losing, and we knew that. We started off the year obviously not the way we wanted to but it just keeps building for us."
The Panthers matched their longest winning streak since they won five in a row from March 11-20, 2012.
They are 11-8-1 under interim coach Peter Horachek, who made his Florida debut in a 3-2 loss at Ottawa on Nov. 9, the day after Kevin Dineen was fired after the team won three of its first 16 games (3-9-4).
"Obviously at that point I was just opening the doors," Horachek said. "I was just telling them how I feel like a team should play and they wanted to play hard for a new coach, but the structure wasn't there and the confidence wasn't there. So I think over a period of time we've won five in a row, and I think it's like seven out of eight, or whatever it is, and now the guys know that they're capable of winning.
"Whatever building you're in, you've got to worry about the Florida Panthers. We have to play our game. We have to play a smart and hard game that we can't always bend around and see how other teams are going to play."
Chris Neil and Jason Spezza scored for Ottawa, which lost 5-2 to the New Jersey Devils on Wednesday.
"We just didn't do enough to win," Spezza said. "We got too passive and found a way to lose."
Senators goalie Craig Anderson stopped 31 shots in his first game since Saturday against the Los Angeles Kings, when he was pulled at 4:18 of the first period after allowing two goals on four shots.
Ottawa coach Paul MacLean called out his team's leadership, which includes captain Spezza and alternate captain Neil, for the Senators' inconsistent play following the loss at the Prudential Center. That defeat marked the seventh straight time Ottawa was unable to follow up a victory with another win.
"Chris Neil scored a goal, Spezza scored a goal, our goaltender competed; I thought that the response from the team was a response," MacLean said. "Now, we didn't win the game, so it's obviously not what we were looking for, but it was a response and that's a place to start."
Pageau was called for high-sticking at 15:30 of the third period when he clipped Panthers defenseman Dylan Olsen in the face.
"It's clear we're feeling pressure now and we're feeling the heat," Spezza said. "We're trying to win hockey games and the effort is there, but we don't execute and 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."
Ottawa has not won consecutive games since the Nov. 9 game against Florida extended its season-high winning streak to three games.
Barkov drew Florida even at 2-2 at 17:11 of the second. The 18-year-old forward, who had two assists in the Panthers' 3-1 win against the Toronto Maple Leafs on Tuesday, set up in the slot to deflect Gilbert's shot from the right point past Anderson for his sixth goal of the season and fifth point in five games.
Hayes scored his fourth goal at 5:39 of the first period to put Florida ahead 1-0. Senators defenseman Joe Corvo's shot was blocked by Krys Barch, and Hayes rushed down ice to take a pass from Shawn Matthias before putting a wrist shot over Anderson's right pad.
Neil tied it 1-1 with his fifth goal at 9:17, with the help of a video review.
Neil drove to the net as Clemmensen stopped Clarke MacArthur's shot from the top of the left faceoff circle. The rebound struck Neil's right skate and went in off Clemmensen, but the goal was immediately waved off by referee Kevin Pollock.
His ruling was overturned when the review determined Neil was in the process of stopping and did not use a distinct kicking motion when his skate made contact with the puck.
Spezza scored a highlight-reel goal on a power play with 29 seconds left in the first to give Ottawa a 2-1 lead.
He took Erik Karlsson's cross-ice pass on the fly and streaked along the right side. Spezza deked Olsen and cut inside to blow past the defenseman before snapping a shot past Clemmensen for his 11th of the season and 650th career regular-season point.
It was the first time the Panthers trailed in four games dating to Dec. 10, when they were behind against the Detroit Red Wings from midway through the first period until 14:38 of the third in a 3-2 shootout victory that launched the winning streak.
Senators forward Mika Zibanejad left the game at 7:02 of the first period. He did not return after sustaining an upper-body injury on a hit into the boards by Panthers defenseman Erik Gudbranson in the right corner of Florida's zone.
"He'll be evaluated [Friday] and we'll see where it goes," MacLean said.
Panthers forward Jonathan Huberdeau was back after missing Florida's two previous games because of a right foot injury.
Defenseman Marc Methot assisted on Neil's goal. Methot returned to the Senators lineup after sitting out three games recovering from the flu.
Florida completes its four-game road trip against the Winnipeg Jets on Friday. Ottawa plays the second of its three-game homestand Saturday against the Phoenix Coyotes.