Fans in the lower bowl stood the rest of the game as the Blues kept hemming the Bruins in their end. Finally, center Brayden Schenn scored into an empty net at 18:31. The sound might have rattled the Gateway Arch.
"We were relentless, I thought, tonight," Blues coach Craig Berube said. "Like, we didn't stop for 60 minutes. That's how I look at the game. Guys were just hounding pucks and on pucks and working and reloading and doing all the little things right. Line changes were great, getting fresh people out there. It was just a pretty good game all around."
The defense is the big question now for Boston.
Bruins coach Bruce Cassidy said Chara took stitches, was very uncomfortable and was advised not to play. Chara asked to be with his teammates, put on a face shield and sat on the bench for the third period. He'll probably need dental work. Defenseman Matt Grzelcyk hasn't played since taking a hit to the head in Game 2, and his status also is uncertain for Game 5.
But that isn't the only question.
The line of Brad Marchand, Patrice Bergeron and David Pastrnak combined for seven 5-on-5 shot attempts in Game 4. The line of Jake DeBrusk, David Krejci and David Backes generated five. The line of Marcus Johansson, Charlie Coyle and Danton Heinen generated four. The line of Joakim Nordstrom, Sean Kuraly and Noel Accari generated two.
"Personally, I think our forwards got to do a way better job with our [defense] out," Cassidy said. "The onus has to go on them. They've got to pull their weight in terms of puck support and helping out the [defense], finishing some plays. We had some lines tonight with very few shot attempts. To rely on a 2-1 game, we can win those games, but they're going to have to pull their weight, especially if these guys are out. That's just the way it is. That's the hand we're dealt."