It was only Johnson's third start of the season, and first at TD Garden. He finished with 32 saves and teammate Milan Lucic scored with 48.6 seconds remaining in OT.
"It was nice," Johnson said. "Especially in the third when I made a couple of saves, you could hear the fans get behind you and it's pretty cool in this arena with these fans."
Backup Bruins goalie Chad Johnson made 32 saves and improved to 2-1-0 this season.
Despite scoring the game-winning goal, Lucic was more satisfied for Johnson's performance.
"He's probably had the toughest job on our team so far," Lucic said. "Obviously with Tuukka [Rask] playing the way that he has and getting almost all the starts, having [Johnson] come in and play big for us is huge, especially here tonight. You need games like that out of your goaltenders and it was great to see him get rewarded here with the big win."
Boston starting goaltender Tuukka Rask is having a phenomenal start to the season with a 10-4-1 record, including a 1.53 goals-against average and a .948 save percentage in 15 starts. Johnson entered Thursday's game with a 1-1-0 record and a 2.53 GAA and a .900 SP in his two starts.
With Rask expected to play a career high in games this season, Johnson understands his role and realizes his playing time will be minimal. Bruins coach Claude Julien has been impressed with Johnson's professionalism and his compete level during practice.
"I thought he played really well, so I'm really pleased for him," Julien said. "I'm sure the players are happy for him, as well."
Johnson admitted he was a bit rusty at the start, which is understandable since he hadn't played a game since Nov. 2. Even though he wasn't feeling sharp, he had to find a way to generate some swagger so his teammates and opponents thought he was ready from the opening drop.
"I felt OK. I can't say I felt great," Johnson said. "It took me a little bit to really get in it mentally. Sometimes you've gotta fake it every now and then and kind of show that you're feeling great. I battled and got more comfortable in the third period and felt great."
Each time the Bruins were in the offensive zone, Johnson was hoping his teammates would pump one in. When Lucic scored in overtime, it was a refreshing feeling for Johnson.
"When I saw him on a breakaway, I kind of put my head down and was like, 'Oh, please score.' These are points we need and there are always teams you think you should get points off of and we really wanted to get the two points tonight."
The two goals Columbus did score came as the Blue Jackets capitalized on a pair of defensive breakdowns by the Bruins. But when Boston needed its goaltender to make the timely saves, Johnson did, especially in the third period, and he also stifled four power-play opportunities for Columbus.
"It was huge," said Bruins forward Brad Marchand of Johnson's performance. "He's worked so hard for us all year long and we really wanted to have a good game for him tonight. He played great and made some huge saves in the third and kept us in it. He did a great job tonight."
Johnson made two of his biggest saves early in the third period with the game tied at 2-2. He kept the Bruins in this one with solid saves on back-to-back two-on-ones. He first stopped the Blue Jackets' Ryan Johansen with a quick right-pad save, then followed it up with another on Brandon Dubinsky.
After Lucic scored at 4:11 of overtime for his eighth goal of the season, the Bruins players came jumping over the boards and mobbed Johnson.
"It's just nice to get two points," he said. "I get in once every two weeks and I try to work as hard as I can in practice to make myself ready for these situations. The guys know there might be a little bit of rust now and then and they battled really hard for me."