Polyphenols are considered to be responsible for some of the health benefits derived from the consumption of red wine. However, the complexity of the polyphenolic constituents of different wines makes it difficult to clarify the specific contribution of polyphenols to such effects. In the present work we fractionated the polyphenols of a red wine and evaluated the effect of each polyphenolic fraction on the growth pattern of the yeast Saccharomyces cerevisiae. We observed a different contribution of the phenolic fractions to the antioxidant potential of S. cerevisiae, the fractions that were enriched with red pigments being the most protective against oxidative stress. Moreover, we found that red wine polyphenols exert their biological activity through the activation of the Yap1 and Msn2 stress-responsive regulators. Above all, the anthocyanins delphinidin 3-glucoside and petunidin 3-glucoside were found to be able to induce the nuclear localization of Msn2, which is responsible for activating the expression of the stress-responsive genes in S. cerevisiae.