I've seen videos of them tearing apart a Land Rover. I'm not sure I'd even land a blow, and if I did, it might be like snapping him with a rubber band. Hard to say, but that's still probably my choice. You might get lucky and then he tears off to stop and trumpet while you curl into a ball in the corner.
Come to think of it, I'd probably try curling up into a ball as my first strategy.