Lundell tied it 1-1 at 14:37 on a backhand from the slot just eight seconds after a power-play expired.
"We're sticking together in here, and there's no quitting in here," Florida defenseman Gustav Forsling said. "We're going to keep fighting until the end here. Obviously, it's a tough loss."
Hamilton gave the Devils a 2-1 lead during a 4-on-4 at 1:35 of the second period. Jack Hughes took the initial shot from the left circle that caromed off the end boards to Hamilton low in the right circle.
Glass pushed it to 3-1 at 8:13 on a highlight-reel tip-in just outside the right post.
"I knew [Lenni Hameenaho] was going to shoot it, but I saw it come in and was just trying to get my stick anywhere around it," Glass said. "Obviously it found the back of the net, so it was a good feeling."
Mercer scored an empty-net goal at 16:23 of the third period to make it 4-1, and Nemec also scored into an empty net at 19:20 for the 5-1 final.
"We've been really good in third periods and closing out games all season long," Keefe said. "I thought we played smart, we played hard and we managed our way through the game really well. I didn't think we started great in our first couple shifts, but 'Markie' was outstanding and then we kind of found our game."
NOTES: Nosek made his season debut after missing the first 60 games with a knee injury. He had two hits and one blocked shot in 10:21 of ice time. ... The last NHL team to win the Stanley Cup and miss the playoffs the following season was the Los Angeles Kings, who won the Stanley Cup in 2013-14 and failed to qualify for playoffs in 2014-15. ... Devils center Nick Bjugstad had two hits and one shot on goal in his 800th NHL game. Bjugstad was acquired by the Devils in a trade with the St. Louis Blues on Feb. 4 for forward Thomas Bordeleau and a conditional fourth-round pick in the 2026 NHL Draft.