Not only did we come into this with a sense of security after having beaten the Warriors but like you said, we were tired in a back-to-back .
The Kings were desperate, coming off a 4 game losing streak. Haliburton was on a mission. Fox might be the best penetrating guard in the NBA and that creates a headache for most NBA teams. Kings actually have a very dynamic backcourt. Top 3 in the NBA probably in a year or two if not THE best backcourt. I would have loved to see Frank get some minutes guarding Fox. Perhaps next time.
Next game we are playing against yet another elite penetrating PG in Lillard. We might lose that game as well unless Frank is back.