(7:4-5) God will make sure that Pharaoh does not listen to Moses, so that God can kill Egyptians with his armies.

(7:4) "Pharaoh shall not hearken unto you, that I may lay my hand upon Egypt, and bring forth mine armies."

(7:5) "And the Egyptians shall know that I am the LORD."
(Who else could be so cruel and unjust?)

(7:9-12) God tells Moses and Aaron that when Pharaoh asks for a miracle just throw your rod down and it will become a serpent. So Aaron throws down his rod and it becomes a serpent. But the Egyptian magicians duplicate this trick, too. Luckily, for Aaron, his snake swallows theirs. (Whew!)

(7:9) "When Pharaoh shall speak unto you, saying, Shew a miracle for you: then thou shalt say unto Aaron, Take thy rod, and cast it before Pharaoh, and it shall become a serpent."

(7:10) "Aaron cast down his rod before Pharaoh, and before his servants, and it became a serpent."

(7:11-12a) "Now the magicians of Egypt, they also did in like manner with their enchantments. For they cast down every man his rod, and they became serpents."
The magicians know the rod to serpent trick too!
Score: Aaron 1, Magicians 1

(7:12b) "But Aaron's rod swallowed up their rods."
But Aaron's rod-snake swallowed theirs, so Aaron gets another point.
Score: Aaron 2, Magicians 1

(7:13-14) God hardens Pharaoh's heart the 3rd time.

(7:13) "And he hardened Pharaoh's heart, that he hearkened not unto them."
Who hardened the Pharaoh's heart?

(7:14) "And the LORD said unto Moses, Pharaoh's heart is hardened, he refuseth to let the people go."
(Well, yeah! His heart was hardened by you.)

(7:15-24)
The First Plague: "The river ... shall be turned to blood."
After the rod to serpent trick, God tells Moses and Aaron to go to the river and convert his rod-snake back into a rod and then smite the river with the rod, which will turn the river into blood. This is the first of the famous 10 plagues of Egypt. Unfortunately, the magicians know this trick too. Shucks! Just how the river could be turned to blood by the Egyptian sorcerers after it had been turned to blood by Moses and Aaron is not explained.
Score: Aaron 3, Magicians 2

(7:15) "Get thee unto Pharaoh ... thou shalt stand by the river's brink ... and the rod which was turned to a serpent shalt thou take in thine hand."

(7:17) "In this thou shalt know that I am the LORD: behold, I will smite with the rod that is in mine hand upon the waters which are in the river, and they shall be turned to blood."

(7:18) "And the fish that is in the river shall die, and the river shall stink; and the Egyptians shall lothe to drink of the water of the river."

(7:19-20) "Take thy rod, and stretch out thine hand upon the waters of Egypt ... that they may become blood ... And Moses and Aaron did so, as the LORD commanded."

(7:21) "And the fish that was in the river died; and the river stank, and the Egyptians could not drink of the water of the river; and there was blood throughout all the land of Egypt."

(7:22) "And the magicians of Egypt did so with their enchantments."
The magicians know the rivers to blood trick too!