After Kucherov scored on the Lightning's first attempt in the shootout, Avalanche center Matt Duchene responded in the second round. Callahan then shot on goalie Semyon Varlamov's glove side and slipped the puck past him off the corner post.
"That's the way it goes, it was a pretty good move and he scored," Varlamov said. "They scored the goals and they won."
"[Bishop] was the reason we got two points tonight," Callahan said. "He was unbelievable out there, especially in overtime. He was definitely our best player tonight."
Avalanche center Nathan MacKinnon tied the game at 2-2 with 6.8 seconds remaining in regulation after the Avalanche pulled Varlamov to bring out an extra skater.
"That was tough because we killed some penalties late," Callahan said. "They end up getting one with six seconds left and we had to regroup and get ready for overtime. We had to kill another penalty at the end of overtime just to get to a shootout."
Callahan gave the Lightning a 1-0 lead at 1:58 of the first period with a power-play goal coming off assists from Alex Killorn and Stralman.
Colorado (19-17-10) tied the game 1-1 less than a minute into the second period when center Ryan O'Reilly took a pass deep in the slot from MacKinnon and flipped it past Bishop high on the stick side.
Defenseman Anton Stralman gave Tampa Bay a 2-1 lead at 4:08 of the third period when he took a pass from Valtteri Filppula off the boards and casually sent the puck to the net. The low bounce seemed to give Varlamov trouble and the puck slipped beneath his pad.
"It was a disappointing to give up the late goal after we had fought them off for so much of the period,” Stralman said. "It was a real strange sequence too, because [defense partner Victor Hedman] broke his stick right there. Still, it showed the character of this team to come back in the shootout and get the win."
Bishop finished with 40 saves in one of his best performances of the season. His biggest save of the second period came when he stopped Marc-Andre Cliche on a 1-on-1 opportunity with less than a minute remaining.
"Bishop played well for them, but we had a lot of chances tonight," MacKinnon said. "It's a tough loss but we battled back; we were down 9-0 in shots early but we came back and put a lot of pressure on them."
In the third period, Bishop faced consecutive power plays, but the Avalanche could not get a clean shot.
"I didn't mind the shots because I thought the defense played well in front of me," Bishop said. "The late goal is always tough to take because you just want to hold on, but you have to turn the page real quick. I thought we handled their pressure well and they really pushed back in the final two periods."
Varlamov made 29 saves for the Avalanche, who will stay on the road and play the St. Louis Blues on Monday.
"For the first 30 minutes we didn't need Bishop a lot but over the last 30 minutes we needed him a ton," Lightning coach Jon Cooper said. "We had a great first period and I thought we had a pretty good start to the second but they turned their game up a notch and their intensity got higher and ours didn’t. We took some penalties late in the third and they pulled their goalie with two minutes left, so basically we were shorthanded for six minutes."
The Lightning finish their three-game homestand against the Vancouver Canucks on Tuesday.