Page 717 — City of Villains, Part 2
If you're going to have a "supposed to lose" fight, perhaps the best way to do it is at the very beginning, in a way that helps establish rather than invalidate the players' desires.
Though really, unless you run the RPG by the book and make it very clear you're not predisposed to the players winning or losing, the "supposed to lose" fight is hard to justify. Sometimes it works best when it's a surprise or a blitz, when the time it takes to lose is at just the right balance. Too fast, and it feels cheap and undeserved. Too slow, and the players catch on and feel the despair of waiting for a situation they can't control to end.
However you do it, the worst thing the "supposed to lose" fight can do to your players is underwhelm them.
Transcript:DM: The Pharaoh's minions are routed in a handful of actions.
Radiance: Just a few mummies? Really now… Is that all you've got?
Pharaoh Phetlock: Now wait just a second! Six on one?! Isn't that unfair for the first fight?
SFX: (WHONK)
Humdrum: Uh… Seven on one, I guess.
DM: Heh heh heh… But yes, this is how our story in the city of Trotham begins… With the villains getting a little bit stomped on by this new band of superheroes. It used to be that villains like Long-Face could render the ponies of Trotham uncontrollably sad without any fear of payback or reprisal… until the Power Ponies showed up and brought him down.
Long-Face (Fluttershy): Oh. I guess that's pretty ironic, actually…
DM: One by one, the most notorious and infamous crooks are taken down, until even the master strategist and shoe enthusiast High Heel… finds herself unable to stay one step ahead of the Power Ponies.
High Heel (Twilight Sparkle): Even with the equipment bonus from all four Stilettos of Dastardly Insight??
DM: It's just not enough.