Javier Aguirre's El Tri climbed to third place in the CONCACAF final 'hexagonal' round on 12 points although only goal difference separates them from the Ticos, who had a disappointing night in San Jose.
Mexico managed to take the lead seconds before half-time as Dos Santos shot from the left side to Keylor Navas' far post. Seventeen minutes after the interval, Dos Santos assisted Guillermo Franco, who widened the gap.
Eight minutes later, Andres Guardado secured the victory after Dos Santos' pass.
Honduras and USA lead the CONCACAF table on 13 points after their respective wins over rock-bottom duo Trinidad and Tobago and El Salvador.