When the Chiefs drafted Patrick Mahomes with the No. 10 pick in the 2017 NFL draft, the writing was on the wall for incumbent quarterback Alex Smith. The then-33-year-old was entering his fifth season in Kansas City, and despite amassing a winning record and leading his team to the playoffs a handful of times, the Chiefs had yet to advance to an AFC championship game—never mind compete in a Super Bowl.

Smith was, however, given one more crack at the starting job for the ’17 season while Mahomes developed behind the scenes. The Chiefs went 9-6 as he again led K.C. to the postseason.

With their seed in the AFC playoff picture prior to Week 17, head coach Andy Reid decided to give the rookie a shot under center in their season finale. Mahomes went on to complete 22 of 35 pass attempts for 284 yards in a 27-24 win—and never looked back.

Smith shared on The Rich Eisen Show this week that this was the exact moment he knew he had essentially lost his job:

“I think as the season went on…” he explained. “There were throws that he made throughout—you know, you’d see on the practice field and you’d start to see how fast he was processing—and then certainly that last game [of the 2017 season]. To go out there in an NFL game and play the way he did, I think everybody that was there that day knew that he was ready.”

The following January, just weeks after the Chiefs’ wild card round loss to the Tennessee Titans, Smith was traded to the then-Washington Redskins and Mahomes was named the team’s starting quarterback moving forward.

It was ultimately a smart decision by Kansas City, who has since gone on to win three Super Bowl titles while Mahomes has cemented himself as one of the league’s all-time great quarterbacks.