Josh Allen shanked a ball so badly during Wednesday night’s ‘The Match’ — he drilled a fan in the back of the head … but, thankfully, the guy somehow wasn’t severely injured.

The wayward tee shot happened on the sixth hole of the event at Wynn Golf Club in Las Vegas … when Allen pushed his ball some 20 yards to the right of the green.

In video of the swing, captured by John of @BackNineBullies, on the 190-yard par 3, you can hear the ball crashing down right on a spectator’s noggin.

The fan immediately crumpled to the ground in pain, yelling out, “Wow! I got it! Oh, my God!” … although, fortunately, he ended up ultimately being all right.

Allen eventually made his way up to the fan … and apologized repeatedly for the shot — and signed a golf ball, a glove and a football as a mea culpa.

We’re told the spectator needed some ice and had a big bump on his head — but he appeared to finish up the event just fine.

As for Allen, his game never quite looked good during ‘The Match’ — he nailed fans continuously throughout the round — and he and Patrick Mahomes went on to lose to Aaron Rodgers and Tom Brady.