This is a spinoff question from Why aren't there any main Federation battleships in the Star Trek universe? The Defiant is presented as a Main Battleship but has also been described as 'just' a "Tough little ship" by Riker. Is there any other in-canon information regarding how well the Defiant has actually stood up against a Galaxy Class type starship in a knockdown drag-out fight or any direct references to firepower/durability simulations, scenarios, in universe comments, etc.?
Are there any ships of Galaxy (or comparable) Class that the Defiant has actually beaten in a fight?
EDIT: From what I've found, the Defiant could be comparable to a modern day U.S. Navy Destroyer. Just as the modern Destroyer, the Defiant is classified as an 'escort vessel'. The Defiant is obviously capable of delivering a decent amount of firepower from a small maneuverable platform as well as being able to take a bit of a pounding but can it really stand toe-to-toe with a Ship of The Line?