Artorias vs Ornstein: You decide.

Random thought I had earlier today. Given what we know about the two, who do you think would win in a duel. Admittedly, we know significant more about Ornstein's fighting style and tactics, but people are starting to put more pieces together regarding Artorias' fighting style and tactics. He's unmatched with a greatsword, uses a great shield, will employ a high pressure offense, and if the Wolf Ring is any indicator, he will not flinch. Ever. So in your opinion, who takes it? The Lion, or the Wolf?