But not everyone knew it was even a goal, including Koepke. The horn didn't sound when his shot went off the post, into the net, off the camera and right back out.
In fact, Tampa Bay came right back down and scored a goal moments later with Hagel ripping a one-timer into the back of the net. But after the officials took a look at the tablet in the penalty box, it was determined that Koepke's shot did indeed go in the net and ricocheted right off the camera and out for his first career goal.
"No, I didn't," said Koepke with a laugh when asked if he knew it went in. "I just kind of had it on my backhand and I saw the goalie kind of lunge. I knew it hit his stick and then I saw it went off the camera and out, but I kind of thought it hit the pipe.
"I looked for a second. The refs didn't wave anything. Everyone else kept playing, so I got back to the bench, and I wasn't super happy. Then Coop and the guys are hitting me on the shoulder like, 'That's your goal!'
"But Hagel had just scored, so I was pretty confused for a second. But then they were like, 'No, yours went in. It hit the camera!'"
It was a well-deserved goal for Koepke, who has worked hard on the forecheck consistently, played a physical game along the boards and made some smart plays throughout the start of his NHL career. He had his father, stepmother and girlfriend in attendance to see him score the first goal that everyone knew would come for the hard-working rookie.
"He gets better every game," Cooper said. "I think he felt that the game two nights ago in Washington, he had two glorious opportunities to score, and he didn't.
"It was just a matter of time. We felt it was coming. It was great to see it tonight.
"It was weird. I don't know how they didn't see it. The puck went in the middle of the net.