Fantastic Four + Namor vs Titans
Reed, Sue, Johnny, Ben, Namor
vs
Nightwing, Beast Boy, Starfire, Raven, Cyborg
Stipulations:
-It's a 2000s lineup for Titans, but you can use current feats minus any one-time amps for current versions (ie, no serpent crown or phoenix force for Namor, no Darkseid amp for Starfire, etc).
-Titans land on top of the Baxter Building prepared for a fight. All building defenses are off. Both sides think they're up against villains, but everybody is in character.
-Neither side has prep, but Sue cloaks and shields her teammates before the match starts.
Round 2:
-Same stips as above, but Miss Martian joins the Titans, while Storm and Black Panther join the F4. Reed equips his team with TP blockers.