In parshat Bo, in Shemot 12:12:
The same is mentioned in Bemidbar 33:4, in parshat Masei.
Perhaps we could say this is not executing judgments against the gods of the Egyptians, but using their "gods." This was the link to parshat va`era, but the rather noticeable fly in the ointment is that this is future tense, not judgments God executed in the past.
But the nice link would have been as follows. Not that Hashem smote the Nile, but that he used the Nile, which they worshiped, as a means of punishing them. And the next plague, of frogs, was also associated with one of their deities, that of Heqet, a goddess of fertility. Apparently, according to Wikipedia,
To the Egyptians, the frog became a symbol of life and fertility, since millions of them were born after the annual inundation of the Nile, which brought fertility to the otherwise barren lands.Furthermore,
Heqet was usually depicted as a frog, or a woman with a frog's head, or more rarely as a frog on the end of a phallus to explicitly indicate her association with fertility. She was often referred to as the wife of Khnum. The beginning of her cult dates to the early dynastic period at least. Her name was part of the names of some high-born Second Dynasty individuals buried at Helwan and was mentioned on a stela of Wepemnofret and in the Pyramid Texts. Early frog statuettes are often thought to be depictions of her.Furthermore, as discussed last week, some say that midwives called themselves servants of Heqet.
Some claim that—even though no ancient Egyptian term for "midwife" is known for certain—midwives often called themselves the Servants of Heqet, and that her priestesses were trained in midwifery.
Even without this explicit connection to a fertility goddess, it is clear that there is a parallel between these frogs which covered all of Egypt, and the Israelites who were also numerous. And how Pharoah commanded the midwives (perhaps associated with Heqet) to kill the Israelite baby boys, and how he commanded the Egyptian people to case Israelite baby boys into the Nile (source of the frogs). There may well be deliberate middah keneged middah here.
And Pharaoh's request, in Vaera, to get rid of the frogs:
Back to the idea of executing judgments against deities, it is not like there is no other Biblical evidence of this. Perhaps, then, as part of the plague of the death of the firstborn, idols also were smashed in various ways. The parallel I am thinking of is what was done to the idol of Dagan, in I Shmuel 5: