190
I fear what he's going to throw at us next fight
(ttrpg.network)
To be fair, they did get some pretty decent damage in on their surprise round. They just didn't get many more chances.
A sneaky DM trick that can do a little better when reeling like that is "HERE COMES A NEW CHALLENGER" where the pushover battle has a slightly more difficult wave of reinforcements afterward, and maybe one more after that with some extra treasure incentive for it to be seen as a challenge rather than a punishment.