I saw a cool trick in a kung fu film once and can confirm it works. You basically get out what they want and throw it at them, not violently, just at the right height to catch (chest height), and they will catch it as a reflex, it's at this point you land a massive punch right in the stomach or better solar plexus. Then when they double over, use your elbows on their head, then ... well I'll leave the rest up to you ;-)