The Aggies' win broke Alabama's streak of 100 consecutive wins against unranked opponents, the longest streak in the AP poll era. The Crimson Tide came into Saturday having won 19 straight games.
Alabama coach Nick Saban said that while the loss itself was disappointing, it doesn't mean that the team's goals are no longer achievable.
"Hopefully we'll learn a lot from this," he said. "We still can accomplish everything we want to accomplish, but we have to do things better than we did tonight. We have to play better, we have to be more consistent, we have to finish drives, we have to get more turnovers on defense, we have to get more stops on defense. There are a lot of things we need to fix."
Throughout the course of his postgame news conference, Saban returned to the theme of a lack of execution in all three phases of the game.
While the offense moved the ball well, it struggled to finish drives inside the red zone, including a Bryce Young interception on the 2-yard line. Saban said there were just too many penalties and too many drops.
While the defense allowed fewer than 100 rushing yards, it struggled in coverage and gave up four third-down conversions. Saban said they needed to create more turnovers than the one interception they had in the first half.
While Alabama blocked a punt on special teams, it also allowed a 96-yard touchdown on a kickoff return by Devon Achane. Saban called the return a momentum swing.
"I'm responsible for all of it," Saban said. "We have to do a better job with our coaches. We have to do a better job with our players."
Young and defensive back Jordan Battle both said a lack of focus contributed to the loss.
"We didn't practice like we usually would, and that bit us tonight," Battle said.
At the same time, Alabama credited Texas A&M for its game plan and execution. Saban said the Aggies were a good team that shouldn't have been overlooked heading into the weekend despite having two losses.
Alabama entered the game as a 19-point favorite. It was the second-largest upset of Saban's head-coaching career, according to ESPN Stats & Information.
"I thought we would have a really tough game here," Saban said. "So when you say this was unpredictable, that's because a lot of people assume that things are going to happen. But really it's about what you do when you play the game."
Saban said he will ask players and coaches to consider what it feels like to lose and what they did to contribute to the outcome, warning, "If we don't play really well, we'll struggle against anyone we play against."
Battle said it's up to him to bring more intensity to the defense "so things like this don't happen again."
The loss to Texas A&M marked the first time Saban didn't beat a former assistant coach head-to-head. On the 25th try, Texas A&M coach Jimbo Fisher, who served as Saban's offensive coordinator at LSU, finally got the job done.
"It doesn't mean anything to me," Fisher said about ending the former assistants streak. "Our football team is learning to play against other great football teams and have success. That's what matters to me."
Calzada had struggled in each of the Aggies' past two games -- back-to-back losses to Arkansas and Mississippi State. But he was sharp against Alabama, completing 21 of 31 passes for 285 yards, three touchdowns and one interception.
"We knew he was a talented guy and he was going to play better and better," Saban said.
Alabama now must regroup before it goes on the road again next Saturday to play Mississippi State. Texas A&M is scheduled to play at Missouri.