Technically—if I were speaking that word aloud instead of typing it, I’d draw it out. “Teeeeeeeeeeeeeeeeeh-ch-ni-ca-llleeeeeeeeeeeeeeeeeee”—it was a tie. Godzilla, back when the character was licensed to Marvel in the late 70s, took on the Avengers. And the Fantastic Four. And SHIELD. He would’ve taken on Spider-man, too, but Spidey was late to the party. And combined might of those vaunted heroes failed to take down the big gray-green titan, which—as a lifelong Godzilla fan, I must attest—is how it should be. Earth’s Mightiest Heroes DID manage (with help from some kid) to convince Godzilla to take a hike. Or maybe Big G just got bored. Either way, there was no clear-cut victor. Superhero fans could hold their heads high after the fight (which took place in issue 24 of Godzilla’s Marvel series) and the Godzilla faithful felt satisfied, too. Sure, there were grousers, and there still are. “The Avengers should’a won!” or “Godzilla would’a totally fried ‘em all!” But neither of those could happen.
Marvel didn’t OWN Godzilla, see. They were just renting him. As part of their agreement with Toho Studios, they had to treat the King of the Monsters with all due reverence. They couldn’t depict him getting his scaly hide handed to him by a bunch of costumed do-gooders. Neither was Marvel about to let their top characters—ALL of them—get schooled by any giant monster, not even the greatest of them all. After the rights for the Godzilla character reverted to Toho, Marvel did pull a sneaky and have a giant green beastie show up, one that looked and acted an awful lot like Godzilla but was never mentioned by name, and then they had this faux-zilla get its arse kicked. That fight wasn’t canon, though, and it wasn’t reeeeeeeeeeeally Godzilla.