Charming a Monster is not losing to it. In fact, all that you need to know about winning/defeating/losing is made clear in the
FAQ in an aptly named important note (quick hint, it's #3). I'm not going to dig for exceptions at this point, but if you're running away, you've lost the combat. Any other situation where you remove Monsters from combat where you don't have to Run Away, you've essentially won, even if you didn't get rewards for the combat.