The rookie goalie was rock solid, making 24 saves, including a couple key stops in the final minutes, in a 2-1 victory against the Winnipeg Jets.
Game 2 of the best-of-7 series is at Winnipeg on Friday (9:30 p.m. ET; CNBC, SN, TVAS, FS-MW).
[WATCH: Blues vs. Jets Game 1 highlights | Complete series coverage]
"Yeah, that was exciting," Binnington said. "Every day in this League is incredible. I'm very humbled to play up here. That atmosphere was really exciting. That was a big game for me and big game for the group to start off our playoffs."
But Winnipeg's Whiteout was on him from the game's opening minute. Trying to return to his net after playing a puck, he collided with Jets forward Mark Scheifele, who was trying to cut between him and the net.
Video: STL@WPG, Gm1: Binnington robs Lindholm with glove
Scheifele was called for goaltender interference, and the Winnipeg fans booed Binnington every time he touched the puck the rest of the night.
"Yeah, they were all over me, but it's a part of the game," Binnington said. "It's exciting. They're passionate like I said. So whatever. We have to handle it. Stay composed, so on to the next game."
That's been precisely his key to success with the Blues this season.
After appearing in two games with St. Louis in December, Binnington was recalled from San Antonio of the American Hockey League on Jan. 5 and made his first NHL start two days later, making 25 saves in a 3-0 win against the Philadelphia Flyers.
From that point, he was St. Louis' No. 1 goalie and set a Blues rookie record with 24 wins (24-5-1) and five shutouts, led in the NHL with a 1.89 goals-against average, and had a .927 save percentage. Binnington was named the NHL's Rookie of the Month in February and March.
"I don't think it was any different than any other game he's played," Blues defenseman Jay Bouwmeester said of the 25-year-old. "He's been great from the first game he played -- he got a shutout and made all the big saves he had to and all the routine ones that are part of the game.
"The first game of the playoffs, everybody's all hyped up and there's a lot of noise around, but I think the bottom line is once the game starts, it's a game. He's not a 19-year-old kid. He's played pro for six years, and I don't think he's bothered by any of this. It's a great experience for him and I'm sure it'll only build his confidence."
Binnington, who was selected by St. Louis in the third round (No. 87) in the 2011 NHL Draft, said he loved the atmosphere of his first NHL playoff game.
"It was cool," he said. "Canadian city. They're passionate fans. So it's exciting and I'm sure they were entertained tonight. We're happy with this win, but now we're focusing on the next game and trying to prepare for that."
Video: Bozak's late goal leads Blues past Jets in Game 1
Binnington's confidence seemed to be building from early on Wednesday.
He handled the puck with composure all night, and the only goal he allowed was a perfect shot through a screen by Jets forward Patrik Laine that went just under the crossbar to make it 1-0 at 13:28 of the first period.
Despite the goal, that confidence was on display late in the game.
With the Blues leading 2-1, Binnington made a save with his right pad on a one-timer from Scheifele in the left circle with 12.4 seconds remaining in regulation.
"He was calm," Bouwmeester said. "I think that helps. I think with goalies, it's confidence and just relying on their routines and ... I don't know, they do some weird stuff. But they're creatures of habit and nothing bothers him. He's confident and everyone lets him go about his business and he's a great guy, so everyone wants to play hard for him."
Tyler Bozak, who scored the tiebreaking goal for the Blues with 2:05 remaining in the third period, said Binnington's performance in Game 1 was unreal.
"He's been a rock for us back there," Bozak said. "He gives us a chance to win every night. Obviously, the play that stands out to me is that save at the end of the game on Scheifele. Obviously, a game saver. He's been doing that for us down the stretch. That's awesome to have a guy like that back there, it gives us a lot of confidence."
David Perron, who tied it for St. Louis early in the third period, smiled when asked why Binnington appeared so calm in his first NHL playoff game.
"It's his personality, probably," he said. "And I think he's just enjoying the ride, too, right now. We need this. He's playing great for us. We need him to keep going like this. And it was cool to see how he played, even with the fans getting on him a little bit with puck plays and different things.
"He got scored on, that first goal, and still kept playing. Amazing."