Joonas Korpisalo made 28 saves for the Senators (34-40-4), who have lost four of five.
"It was a hard-fought game. There was not a lot of time or space out there," Ottawa coach Jacques Martin said. "A couple of mistakes we made in the first period cost us goals. We had a couple of good chances, [Stolarz] made some nice saves. We battled hard. ... If it wasn't for the [mistakes], I thought we played a good, strong game."
Lundell gave the Panthers a 1-0 lead at 12:02 of the first period with a power-play goal. He took a stretch pass from Stolarz, catching Ottawa in a line change, and beat Korpisalo five-hole on a breakaway.
"The game is going towards playoff hockey," Lundell said. "We want to be ready when Game 1 starts. It's going to be pretty simple. We just got to not always try to make a play. Sometimes just try to do a little easier solution and try to get speed and play fast hockey."