The Rock proved ring rust is just a myth on Saturday — returning to the squared-circle for the first time since 2016 at WrestleMania 40 … and ending the epic match with the win!!

The Final Boss and Roman Reigns paired up against Cody Rhodes and Seth “Freakin’” Rollins in a tag-team match to cap off WWE’s first night of festivities … and the whole thing was fireworks from start to finish.

In fact, action broke out outside of the ropes numerous times … and Cody and Seth were in for a world of pain, as Rock — a real-deal exec with WWE’s parent company, TKO — made it clear to the ref early on … if he counted, he’s fired.

Rock secured the dub with a vicious People’s Elbow … but not before giving a shout-out to Cody’s mom.

Rock pinned Cody after the move … and the win comes with some serious weight, as Rhodes’ fight for the Undisputed WWE Universal Championship will now go down under Bloodline rules.

The wild match was hopefully a sign of more awesome moments to come on night two … when Cody and Roman face off for the whole shebang.