Cooper caught 11 passes for a career-high 226 yards, including a 53-yard touchdown, but he could have had another 20 or so yards or maybe even a touchdown if everything had gone the way he planned.
Instead, quarterback Dak Prescott's pass deflected off Cooper and into the waiting arms of cornerback Jaire Alexander for an interception, ending a Cowboys' scoring chance and allowing Green Bay to score its first touchdown.
For the rest of the game, Cooper kept thinking about that play.
"The only thing that was really on my mind was the dropped ball," he said. "The turnover I created. I feel like it gave them a lot of momentum in the game."
The catches and yards piled up, but the Cowboys (3-2) could never climb out of a hole that got as deep as 28 points in the third quarter.
Cooper became the first Cowboy with multiple 200-yard receiving games; he caught 10 passes for 217 yards and three touchdowns in an overtime win against the Philadelphia Eagles last season. Sunday marked the third 200-yard game of his career, but it seemed almost hollow. (By the way, had he maintained his balance on a 46-yard catch on the second drive, he could have had the best receiving day in franchise history.)
"It was, 'I got it.' That's what I was thinking," Cooper said of the fourth play. "Those are the worst three words in football. I feel like I had it. It was an easy catch, took my eyes off it because I was focused on the touchdown."
Instead, it was the first of Prescott's three interceptions that ruined what was otherwise a career day for the quarterback.
He had the most passing yards of his career (463), completing 27 of 44 attempts. In addition to the 53-yard touchdown to Cooper, he had a 40-yard pass to Michael Gallup, who had 113 yards on seven catches in his first game back from knee surgery. The 463 passing yards by Prescott were the second-most in a game in team history. Only Tony Romo had more (506 yards) in a 51-48 loss to the Denver Broncos in 2013.
Prescott had to throw for that many yards because of the deficit that was created partially by the turnovers.
Prescott's previous high was 455 yards in the aforementioned overtime win against the Eagles in December.
"I don't care how many yards I had or anything like that. Three interceptions and a loss, I don't care what career high I have. None of that matters," Prescott said. "Amari saying that, I think, is an example of guys in the locker room, a lot of guys on our team look in the mirror before they point fingers."
Only once before had Prescott been picked off three times: in a 37-9 loss to the Eagles in 2017, when running back Ezekiel Elliott was suspended. The first pick Sunday can be attributed to Cooper, but "I could've put the ball two more inches in front of him," Prescott said.
The third interception can be attributed to a missed penalty on cornerback Kevin King, who swiped at Gallup twice before Prescott threw the pass. Because Jason Garrett lost a previous replay challenge, the coach did not have a chance to challenge that play.
Instead of continuing an improbable comeback, Prescott was intercepted with 10:21 to play. The Packers turned that takeaway into three points for a 17-point lead.
"You look around the league, a lot of quarterbacks throw it that way to make sure they throw the flag there," Prescott said. "It didn't happen. You've got to move on."
Prescott's second interception was his fault, as he admittedly forced a throw into coverage to receiver Randall Cobb in the second quarter.
Prescott is on pace for 19 interceptions. In his first three seasons as a starter, he totaled 25 interceptions. He had four as a rookie and eight last season. Three of the six interceptions this season can be put on somebody else -- even if the stat column says otherwise.
"I pride myself on taking care of the ball, so when you get back to the locker room, and you have a game like this, and you've thrown three interceptions, it's not a good feeling," Prescott said. "But I promise you I'll get better because of it."
"As long as we have those type of guys on our team, we're going to be fine," Prescott said. "We're going to keep getting better. We're going to be able to take things like this on the chin, learn from them and get better because of that, simply because [of] that attitude."