ATLANTA — You saw it before a play was run in the Rams’ 13-3 Super Bowl LIII loss to the Patriots on Sunday night inside ear-splitting Mercedes-Benz Stadium.

Jared Goff looked petrified during Gladys Knight’s stirring rendition of “The Star-Spangled Banner.”

The third-year Rams quarterback had that textbook deer-in-the-headlights look of a young quarterback playing in his first Super Bowl — the biggest game of his life with Tom Brady playing in his ninth Super Bowl on the opposite sideline — as he stood frozen in his uniform during the anthem.

Goff had a faraway look in his eyes and his right hand looked like it was shaking as he tried to clutch his left chest with it as Knight completed the song.

You could have passed it off as nothing … until they started playing the game.

As unsettled as Goff looked on the sideline was as discombobulated as he performed on the field in the game.

“It’s the toughest loss I have ever had,’’ Goff said. “It kills. It hurts me so much knowing how well our defense played. To play that well defensively and us not hold up our end of the bargain … it’s terrible.’’

The play that defined Goff on this night — a bizarre, choppy, low-scoring 13-3 Patriots win before 70,081 fans that consisted mostly of throaty New England supporters — ironically came at a time when he finally appeared to have found a rhythm on what was a colossal struggle of a game.

It was a mistake by Goff born of pure panic and it effectively ended the Rams’ chances of tying the game. Goff, on a second-and-10 from the New England 27-yard line with the Rams trailing by a touchdown, threw a sickly pass off his back foot toward the end zone.

The ball, like a butterfly, landed so softly and surely in the arms of Patriots cornerback Stephon Gilmore with 4:17 remaining in the game, it looked like a father soft-tossing a ball to his young son in a backyard game of catch.

It looked too easy. Gilmore caught the gift that dropped from the sky and lay on the turf at the New England 4-yard line, cradling the ball as if he would never let go of it.

“That’s my fault,’’ said Goff, who held his helmet with both hands when Gilmore caught the ball. “I can’t put us in that situation. I knew they were bringing a cover-zero blitz there and I tried to hit Brandin [Cooks] on a go-ball and Gilmore was too far off for me to make that decision. It was a bad decision by me. I have to be better.’’

The turnover — the Rams’ only one of the game — led to a 72-yard New England drive that ended in a 41-yard field goal by Stephen Gostkowski for a 13-3 Patriots lead with 1:12 remaining.

Goff finished 19-of-38 for 229 yards and that crushing interception. Those numbers were deceiving, though. Goff, who was also sacked four times, looked even worse. He looked lost at times.