Yup, everything should be fine. Lucky you because if your multimeter was on lower OHM measurement or current measurement, it would have either damaged the meter or melted the fuse inside.
Even if that happened, current was in order of milli-amps. There is no way UPS could be damaged.
I've done that kind of thing many times. I have several cheap meters for times I'm not so sure what I would encounter. Nice bench meter comes out only when I'm sure what I'm looking at, or when accuracy is required.