Never try and run upstairs in the dark wearing flip flops. That is the valuable lesson Brad Pitt has learned the hard way.

The Hollywood hunk appeared at a charity event at the weekend sporting a large bruise just below his eye on his left cheek, raising concern among fans as to how he may have injured himself.

Brad, 51, released a statement to People, revealing: “This is what happens when you try to run up steps in the dark, with your arms full, wearing flip flops.

“Turns out if you then try to stop your forward momentum with your face, the result is road rash.

“Regardless, I wasn’t going to miss the Autism Speaks benefit the night after – wonderful people and I was honoured to be a part of this important event.”

Jack Black was MC at the third annual Light Up The Blues Concert at the Pantages Theatre in Hollywood at the weekend.

The School Of Rock star helped auction off a Fender guitar signed by the performers from the event, all of whom have autism, which Brad ended up winning after bidding 23,000 dollars (£15,000).

Other stars at the event included Christina Applegate, Gary Cole and Amy Brenneman, and the night ended with all of the performers – Spencer Harte featuring Petra Haden, Nick Guzman and Matt Savage – singing Neil Young’s Rocking The Free World.