It was a nightmare start, but the ending was much better for No. 5 Texas A&M.
The Aggies avoided a huge upset against Colorado after Zach Calzada hit Isaiah Spiller for an 18-yard touchdown pass late in the fourth quarter to secure a dramatic 10-7 victory.
Calzada was pressed into action when starting quarterback Haynes King went down with a leg injury in the first quarter and didn't return.
For three quarters, Calzada struggled as he had just six first downs and 126 yards before a 13-play drive in the fourth quarter. Calzada appeared to score a go-ahead touchdown on a 13-yard run, but replay overturned the score when it was ruled he fumbled before the goal line and Colorado recovered.
Undaunted, Calzada led the game-winning drive on the next possession. He hit Devon Achane for 25 yards over the middle to get the ball in Colorado territory and then found Spiller out of the backfield in the end zone on third-and-9 with 2:41 left for the go-ahead score.
Texas A&M then stopped the Buffaloes on fourth down and ran out the clock for a win that avoided a damaging loss to its College Football Playoff hopes. However, the Aggies still have major concerns on offense as Calzada will likely be the starter for at least the short-term. King was seen on the sideline with a walking boot and crutches in the second half.
Given all that occurred in the first half, Texas A&M was fortunate to get into the locker room down 7-3.
The Aggies offense never got untracked after King was sidelined on its second possession that ended with a missed field goal. Calzada completed just 2 of his first 8 passes for 2 yards as the offense didn't register a first down until less than two minutes left in the second quarter.
Colorado, meanwhile, was finding success mixing runs and passes to keep Texas A&M off-balance. Jarek Broussard scored the game's first points on a 2-yard touchdown run late in the first quarter to put the Buffaloes ahead.
The second quarter was defined by missed opportunities as one Colorado drive ended with a missed field goal and then one was stopped on fourth-and-1 from the A&M 5.
The Aggies finally got points on their final drive of the half as Calzada had his best moments, hitting four passes and setting up a 41-yard field goal by Seth Small.
Follow colleges reporter Erick Smith on Twitter @ericksmith
This article originally appeared on USA TODAY: College football: Texas A&M loses QB, needs late TD to beat Colorado