The Philadelphia Eagles' quick thinking to challenge a play while the 49ers missing their opportunity to throw the red flag has put San Francisco in a difficult situation to start the NFC Championship Game on Sunday at Lincoln Financial Field. 

After the 49ers stopped the Eagles on the San Francisco 37-yard line and Philadelphia opted to go for it on fourth-and-3, quarterback Jalen Hurts connected with DeVonta Smith on a 29-yard pass completion. However, that catch shouldn't have counted. 

Rather than celebrating the play, Smith had the entire team rushing to the line of scrimmage, and for a good reason. The 24-year-old didn't maintain possession of the ball while making his catch.

As a result, Philadelphia's offense got the play off before 49ers coach Kyle Shanahan could challenge the ruling on the field of a catch, which eventually led to a 6-yard rushing touchdown by running back Miles Sanders. 

A few moments later, the Eagles' quick thinking continued on the 49ers' first possession of the game. After Haason Reddick hit rookie quarterback Brock Purdy, the initial ruling on the play was an incomplete pass. 

But rather than letting the 49ers get their play off, Eagles coach Nick Sirianni quickly challenged the ruling. Eventually, the play would be overturned and ruled a fumble, with Philadelphia gaining possession. 

RELATED: Jimmie Ward, A.J. Brown get in heated exchange before 49ers-Eagles NFC clash

To add injury to insult for the 49ers, Purdy sustained an elbow injury on the play and is questionable to return.

The game didn't started the way Shanahan and Co. would have hoped, and the bad news continued as the Eagles took a 21-7 lead into the locker room at halftime.