JSA: Doctor Fate, Doctor Mid-Nite, The Flash, Green Lantern, Jakeem Thunder, Jesse Quick, Lightning, Mister America, Mister Terrific, Obsidin, Wildcat, Anna Fortune, Atom Smasher, Citizen Steel, Cyclone, Hourman, Judomaster, King Chimera, Power Girl, Sandman, Stargirl, Wildcat, Hawkman, Hawkgirl, Damage, Wildcat 2.
Avengers: Captain America, Thor, Maria Hill, Protector, Red Hulk, Iron Man, Hawkeye, Spider-Man, Spider-Woman, Wolverine, Ant-Man, Hulk, Black Panther, Black Widow, Moondragon, Ms. Marvel, Sub-Mariner, Quicksilver, Scarlet Witch, She-Hulk, Mr. Fantastic, Thing, Wasp, War Machine, Wonder Man, Vision, Luke Cage.
They fight in London. No interference from the outside. Fight can extend to entire Earth, or beyond.
First fight at their regular power levels. Second at their most powerful. Who wins and why??