Promoted Plymouth made a losing return to League One as they suffered a 2-1 setback at Peterborough.The Pilgrims fell behind just four minutes into their opening fixture of the season when a Leo Da Silva Lopes cross took a wicked deflection off Gary Sawyer - who was credited with an own goal - and flummoxed goalkeeper Luke McCormick.Plymouth conceded again two minutes into the second period as their appeals for a foul were ignored after Posh debutant Jack Marriott robbed defender Sonny Bradley. Marriott then laid a second goal on a plate for Junior Morias.Terrific saves from McCormick kept Derek Adams' side in the contest as he denied Doughty and Marriott before Plymouth halved their arrears.Substitute Gregg Wylde marked the start of his second spell in Pilgrims colours by firing past the previously unbeatable Jonathan Bond with 14 minutes to go.On-loan Posh keeper Bond earlier denied the visitors on a host of occasions, most notably when pulling off a stunning double-save from Joel Grant and Antoni Sarcevic.