Mrazek, who missed 38 games this season (31 with a broken thumb, seven more for a lower-body injury), was 6-2-3 with a 2.06 GAA, .923 save percentage and three shutouts in 12 regular-season games, all starts.
Mrazek had played in 27 Stanley Cup Playoff games before Thursday, going 11-14 with a 2.31 goals-against average, .914 save percentage and five shutouts.
Forward Sebastian Aho, who had a goal and two assists, expected Mrazek to be strong in his return.
"He made some huge saves tonight and obviously you're banking on your goalie," Aho said. "I had no doubt in my mind he'd be good tonight. He was himself out there, made huge saves and gave us a chance to win a hockey game. and that's what happened."
Brind'Amour said there wasn't anything Mrazek could've done on the two power-play goals that beat him in the second period. One was a tic-tac-toe play that ended with Brayden Point scoring the Lightning's first goal. The second came when Nikita Kucherov got his own rebound and passed to Alex Killorn, who scored.
"Kind of weird bounces that end up on great players' sticks. They're not going to miss those. He was good," Brind'Amour said. "Did I expect him to be like that? I didn't know what to expect, he's been out for so long. He's a battler."
RELATED: [Complete Hurricanes vs. Lightning series coverage]
Mrazek's battling helped offset another forward injury for the Hurricanes. Warren Foegele went to the locker room holding his left shoulder after he was hit by Lightning defenseman Erik Cernak with 2:20 remaining in the second period. Foegele returned to play two shifts in the third but left for good after getting sandwiched between Lightning forwards Steven Stamkos and Blake Coleman four minutes into the period.
Brind'Amour said he hopes to know more Friday about Foegele's status. The Hurricanes are already without Nino Niederreiter, who has missed all three games of the series after sustaining an upper-body in practice on Saturday, and Vincent Trocheck, who sustained a lower-body injury after colliding with Foegele late in the second period of Game 2 on Tuesday.
The Hurricanes will have questions at forward heading into Game 4 but not with their depth at goaltending.
"He was incredible," Hurricanes defenseman Brett Pesce said of Mrazek. "That says a lot about him. He didn't start playoffs because 'Ned's' been so good. We have two No. 1s, and I'm so proud of Petr. I couldn't be happier for him to stick with it, waited for his turn and obviously he was huge for us tonight."
