The Flyers pushed their string of victories to a season high four in a row on Thursday with a 3-2 win over the Penguins. Ilya Bryzgalov made 25 saves as Philadelphia moved a point ahead of Pittsburgh for first place in the Atlantic Division.
"We fought hard. We knew it was going to be a big battle," Hartnell said.
Philadelphia continued to get scoring from Claude Giroux in Thursday's win. Giroux notched an assist to give him 18 points in his past 11 games and a league-leading 37 on the season off 16 goals and 21 assists.
After taking on a Pittsburgh team that was without captain Sidney Crosby, the Flyers host a Lightning team that lost St. Louis prior to Thursday's game with the Rangers after he was accidentally hit in the face with a puck by teammate Dominic Moore during the morning skate.
St. Louis, who is second on the club with 22 points, is out indefinitely and saw his consecutive games played streak end at 499.
Moore did his best to atone for his mistake, scoring a game-tying goal while shorthanded with 1:57 to play in the third before tallying the lone shootout goal in a 3-2 win over the Rangers.
"We faced a lot of adversity. Sometimes it's just a matter of sticking with it long enough," said Moore.
The Lightning posted a 2-1 overtime over the Flyers in the first of four meetings between the clubs on Nov. 9. Brett Connolly scored the game-winner and Dwayne Roloson made 14 saves.
Hartnell had the goal for the Flyers.
Tampa Bay moved to 4-0-1 in its last five versus the Flyers and has won two straight and 11 of its past 15 in Philadelphia.