Competitive solvation of the excess proton in protonated mixed methanol-water clusters [H+(CH3OH)(m-)(H2O)(n), m + n = 4] has been characterized by vibrational predissociation spectroscopy in combination with density functional theory calculations. The solvation topology of the clusters can be classified as (1) the closed shell, in which a hydronium ion H3O+ is fully solvated by three neutral molecules forming a complete solvation shell, and (2) the open chain, where the excess proton is tugged between two mixed subunits in a linear chain. The existence of these two types of isomer is verified from a close examination of the characteristic free-OH and hydrogen-bonded-OH stretching modes in the spectra. It is found that sequential replacement of the water molecule in H+(H2O)(4) by methanol redistributes the population between the closed-shell and the open-chain isomers. While the excess proton is preferentially taken by methanol (instead of water) in the chain configuration, it can be either localized as CH3OH2+ or delocalized as CH3OH...H+...CH3OH at m greater than or equal to 2, depending sensitively on the number of the methanol molecules and the symmetry of the cluster isomers. In contrast to that of NH4+(NH3)(m)(H2O)(n), m + n = 4, previously studied, this work provides a clear picture of competitive solvation of a charge between the constituent solvent molecules within a cluster.