brawl is a dual layered game, you'd either need a dual layered DVD and preferably Softmii, but even then, I'm not sure if it'd work. There are ISO's online that are cut to 4.7, but I heard things like cutscenes and music are taken out. If you burn those on a Good DVD, it should work.
But it is full suggested you get Softmii (not the CSM, but the guide just to get the features), for the best compatibility.