Source: Bang ShowbizShia Labeouf got into a fight in a bar - because someone stole his hat.The 26-year-old actor was in good spirits and happily posed for pictures with fans at the Hobhoblin pub in New Cross, south London , but the mood turned sour when a fellow drinker "jokingly" swiped his baseball cap and refused to give it back.One onlooker said: "No one could believe that a well-known Hollywood star had rocked up at a bar in dingy south London. Everyone was getting photos taken with him."The row started when this guy took his hat. I think he was joking, but Shia didn't like it."The guy just took it off him and wouldn't give it back. He tried to get it back and they ended up tussling."It was handbags really. But it shows that even Hollywood stars can't avoid trouble down this way."Shia went to the pub with his 'Nymphomaniac' co-star Mia Goth, with the bar's landlord Mark Harris saying the pair were in the area visiting the 19-year-old actress' family.He told The Sun newspaper: "Her mum lives just down the road. She came down to see her mum and he tagged along."He did get a bit frustrated and there was a bit of a scuffle."The fight was calmed by fellow drinkers and Shia left the bar in a taxi.Police were not called over the incident.The 'Transformers' actor - who was involved in two bar fights last year - recently expressed his belief he has learned from his past mistakes and begun to calm down.He said: "I've made mistakes along the way, but I'm learning. I'm more comfortable with myself, and I'm calming down. I think mosttwenty-something men go through similar struggles and start seeing what boundaries and what rules are. "It's about pushing limits and trying to find yourself. I've never been able to learn from other people's mistakes - I'm not that smart - so I usually learn by trial by fire."