Surfer could take out most of the JLA with one blast....... he could probably destroy the planet if he wanted to...... then he'd just be fighting the space capable Leaguers
Gender: Male Location: Planning to take over the WORLD!
phoenix, king thor, odin, etc . . . are not superhoeroes. they are cosmic entities. and a pissed surfer absolutely could NOT take out the entire JLA. it's debatable he could even take out a single pissed off superman. throw in GL, jonn jonzz, flash, WW et al., all of who could give supes himself a run . . . surfer would get crushed. in an old SS vol 1, a very pissed off surfer tried to take out thor and could do no more than stalemate him - AND the surfer's power was even being augmented by loki! in that issue, the surfer says:
"i have seen his mallet's magic - it is truly mightier than my cosmic force."
in that battle thor was HOLDING back from using his full power against a loki enhanced surfer. thor also absorbed SS bolts with his hammer. also in that issue SS did manage to battle loki to a draw.
i've always been a bit amazed at the luv SS get's on this site. i like him, think he's powerful, but the whole JLA - c'mon . . .
so, to answer the thread question - no, i don't think anyone ONE superhero (ie non-cosmic entity) can defeat a team made up of the universe's most powerful heroes.
He also beat the crap out of Eradicator and Steel, forced Superboy to do what he wanted to,, without much effort. He's got a good chance of beating the JLA.