The Iliad, Book 5

Diomedes starts kicking ass for the Greeks.  Kills Pandaros, breaks Aineias's hip.  Strikes Aphrodite (with Athene's permission) as she ferrets Aineias away.  Apollo keeps him safe.  In response to Athene, Ares joins alongside Hektor to push back on the Greeks, led by Menelaos and Antilochos.  As Hektor wreaks havoc, Hera and Athene look down with concern.  Athene fights directly alongside Diomedes, allowing him to strike a blow on Ares, who withdraws, to be healed by Zeus.  Sides are even again.