Basically we reached a pivotal point in our match and this happened:
Judge: Gate card, o-
Both of us:
ROCK HAMMER!!!!!!!*The two battle gear collide in midair*
Judge: Uh... what were you going to do?
NP: I was gonna Rock Hammer his VILANTOR.
Kohdok: I was gonna Rock Hammer his
Rock Hammer.
Judge:

Now we both had this move ready. I actually put in my post before NP even rolled that the instant the card flipped over, I was going to Rock Hammer his Rock Hammer because I knew he was going to Rock Hammer my Vilantor if I didn't.
The question is: Which effect happens first? Also, is there a "Last-in, First-out" clause so even if mine went second, does its timing cause the first effect?
Both Rock Hammer plays were legal. It was on a bronze card, My Rock Hammer was Bronze and NP was using a Ventus Bakugan.