Brad Pitt shares how he got that nasty bruise on his face

Brad Pitt didn't let a bruise stop him from attending a charity event over the weekend. The dad-of-six revealed that his injuries were nothing to worry about and were simply a result of his misguided attempt to run in flip flops in the dark.

"This is what happens when you run up steps in the dark, with your arms full, wearing flip flops," Brad explained via a spokesperson. "Turns out if you then try to stop forward momentum with your face, the result is road rash.

Brad Pitt revealed his cut face was a result of running in flip flops Photo: Getty Images

"Regardless, I wasn't going to miss the Autism Speaks benefit the night after – wonderful people and I was honored to be a part of this important event."

The 51-year-old appeared on stage to address the crowd of 3,000 people at the third annual Light Up the Blues concert in support of the Autism Speaks charity. He later showed his charitable side by placing the winning bid of $23,000 on a Fender guitar signed by all the performers at the concert.

The annual event was established in 2013 by musician Stephen Stills and his wife Kristen, who have a son with autism. Other stars who attended included Jack Black and Neil Young, who joined his old bandmate Stephen for a special performance.

Brad Pitt addressed the crowd at the Autism Speaks concert Photo: Getty Images

Brad has been based in New Orleans in recent weeks to work on his new film Big Short, which he is both starring in and producing alongside an A-List cast including Ryan Gosling, Christian Bale and Steve Carrell.

No doubt the actor enjoyed the opportunity to be reunited with his wife Angelina Jolie and their kids during his return to Los Angeles. Angelina was seen flying into LAX with their eldest son Maddox and her brother James Haven on Saturday following her appearance at the United Nations Security Council Meeting in New York.

During her visit, she urged that there is a moral duty to help: "We cannot look at Syria, and the evil that has arisen from the ashes of indecision, and think this is not the lowest point in the world’s inability to protect and defend the innocent. It is sickening to see thousands of refugees drowning on the doorstep of the world’s wealthiest continent. No one risks the lives of their children in this way except out of utter desperation."

Angelina spent her Friday at the United Nations Photo: Getty Images