With the 49ers in desperate need of a spark, Brandon Aiyuk gave it to them — with a huge assist to Kindle Vildor’s facemask.

As San Francisco trailed by 14 in the middle of the third quarter, Brock Purdy heaved a pass downfield to Aiyuk, and the ball went beyond the receiver’s reach and hit off of the right hand and facemask of Vildor, the Lions cornerback.

Aiyuk kept running forward and was able to stretch out to make the catch to complete a wild 51-yard completion.

Three plays later, Aiyuk caught a 6-yard touchdown as the Niners cut their deficit to seven.

The miraculous catch quickly seemed like a turning point, as Lions running back Jahmyr Gibbs fumbled on the first play after the subsequent kickoff, and the 49ers took over at the Detroit 24-yard line.

Christian McCaffrey scored a 1-yard rushing touchdown three plays later, and just like that the 49ers tied the game 24-24 after trailing by 17 points at halftime.

Those two touchdowns came within a span of 2:15 of game time.

It had been all Lions in the first half, with Detroit rushing for three touchdowns, but their quest to reach their first Super Bowl in franchise history has turned upside down in the third quarter.