Roshi wins pretty handily. Unlike Pui Pui, he's displayed an array of techniques, some of which have significant hax (Hypnosis and Mafuba, especially). Even if we assume it's his buff state, I don't believe that would be detrimental from how effectively he used it in FnF, not to mention that given it takes place at the Tenkaichi Budokai, he'd be far more attuned to the battle arena than Pui Pui.