Godzilla would win right off the bat if he just charged his mouth laser and zapped that overgrown monkey before he could get close. But Godzilla is all about putting on a show, so he’d wait until the last second before whipping that out. By then, Kong would have already destroyed him in a hand-to-hand melee. Sure, Godzilla’s got a solid tail-whip, but his little t-rex arms can’t throw down against Kong’s massive forearms.
Regardless, I’m predicting a stalemate. Followed by several other stalemates in sequels 2 Godzilla 2 Kong, Godzilla vs. King Kong 3: Tokyo Drift, ‘Zilla & Kong, GodKong 5, and Godzilla vs. Kong vs. Betty White. But in the 7th sequel, premiering circa 2030, they’ll both realize that they’re just pissed off because they’ve been females trapped in male bodies and the government will build a giant surgical knife so the monsters’ outward appearance can reflect who they are on the inside. Bold. Brave. It will win five Oscars.