Former child star Danny Bonaduce was slashed across the chest and arm with a knife during a recent failed attempt to mug him.The one-time Partridge Family star claims the incident happened while he was working out in a Los Angeles park.The 49-year-old tells the National Enquirer, "These wild-eyed dudes walked up to me and my girlfriend and one of them whipped out a carpet knife and demanded money."Bonaduce, a martial arts expert, adds, "I'm tough, but I'm not invincible. I couldn't run because I was exhausted, so I decided to stand my ground. I said to the guy, 'There are two kinds of guys who carry knives - the kind who aren't afraid to stab someone and the kind who don't have it in them. I don't think you have it in you.'"Bonaduce approached the man, and was attacked, before the thugs fled.The star - who wasn't seriously hurt - adds, "The guys took off running, and I let them go because I was too tired to go after them. Besides, I wasn't about to leave my girlfriend standing there by herself."