两虎相争，必有一伤

lit. when two tigers fight, one will get injured (idiom); fig. if it comes to a fight, someone will get hurt

lit. when two tigers fight, one is sure to be wounded (idiom); fig. if it comes to a fight, someone will get hurt

lit. two tigers fight (idiom); fig. a dispute between two powerful adversaries; a battle of the giants

lit. two tigers fighting (idiom); fig. fierce contest between evenly matched adversaries

lit. the mountain can't have two tigers (idiom); fig. this town ain't big enough for the two of us

lit. when the snipe and the clam grapple with each other, the fisherman catches them both (idiom); fig. when two sides are locked in dispute, it's often a third party that benefits