“Lost” star Matthew Fox, who plays hunky take-charge stud Jack Sheppard on the ratings-hot survival show, just made his bones as a real-life hero — singlehandedly rescuing a mechanic who lay crushed and gasping under a massive SUV! Fox had been cruising through LA’s twisty Laurel Canyon when he spotted a tow truck parked in front of a soccer-mom-sized SUV — flanked by a woman waving madly and screaming for help. Fox pulled over and sized up the horrifying situation: The tow truck mechanic had jacked up the disabled SUV and crawled underneath to investigate — but the jack malfunctioned and the heavy vehicle suddenly slammed down, pinning him like a bug. The burly mechanic was conscious, but gasped: “I can’t move!” Desperate, Fox checked the jack, immediately figured out what had gone wrong — then actually managed to get it working again. Holding his breath, Fox carefully ratcheted the vehicle up a few inches — then reached underneath and dragged the trapped mechanic to safety. The guy was gasping and shaking, but hadn’t suffered any serious injuries. He and the woman, who was still borderline hysterical, kept thanking Fox and shaking his hand until Our Hero drove off into the sunset . . . as heroes always do!