The IAM Cycling rider edged out compatriot Elia Viviani and Spain's Jose Joaquin Rojas in a sprint finish to the line of the 175.5-kilometre ride from Santanyi to Campos.
France's highly-fancied Nacer Bouhanni was back in fourth with British rider Ben Swift in seventh.
Friday's 149km stage takes the riders from Andratx to Mirador d'Es Colomer.