Forum:Sakuretsu Armor Prevents Damage?

Skip the next paragraph if you wanna get straight to the query, with no context.

In a recent tournament, I lost a very close duel (And, consequently, a very close match) due to a ruling issue. Basically, my opponent declared an attack and I chained a Sakuretsu Armor, believing this would prevent my loss of life. My opponent argued that, although his monster was destroyed, Sakuretsu Armor didn't state that it negated the attack, so I still took damage (And lost). I argued that the chain was resolved before damage calculation, and with no monster to attack with, he couldn't hurt me. He got a judge involved, and the judge ruled in his favor. For future reference, I was wondering if anyone could clear this up for me, because I'm positive I should have won that match.

In short: If Sakuretsu Armor is resolved, destroying the attacking monster, is damage calculation applied, monsters destroyed, et cetera?