San Diego built a 6-1 lead through four innings and easily held on to end a three-game losing streak.
The Padres took the lead with a four-run third, during which Maybin had an RBI single and scored on a two-run double from Jesus Guzman.
Maybin singled in another run in the fourth, scored in a three-run seventh on a single by Chase Headley and crossed the plate in the eighth on a double by Yonder Alonso.
Only one of the 18 San Diego hits was a homer, that contributed by Nick Hundley in the ninth.
Two of New York's runs came on a sixth-inning homer from David Wright.
Eric Stults (1-0) won for the first time in a San Diego uniform after being claimed on waivers from the Chicago White Sox last week. Stults, who had a no-decision in his San Diego debut against Atlanta, limited the Mets to one unearned run on four hits through five innings.
Jeremy Hefner (0-2), given a spot in the New York rotation when Miguel Batista went on the disabled list, was roughed up for six runs on nine hits in 3 2/3 innings to take the loss.