Plymouth playmaker Graham Carey tucked away a stoppage-time penalty winner as Argyle came back from 1-0 down to beat League One play-off rivals Peterborough United 2-1 at Home Park.The Posh went ahead when the league's leading scorer Jack Marriott took his tally to 26 goals with a superb 10th-minute finish as he pounced on a bouncing through ball to lob stand-in goalkeeper Kyle Letheren.Argyle's best move of the first half resulted in their leveller.The greens swept the ball down the left wing and skipper Gary Sawyer's pinpoint pacey cross to the near post was deftly headed into the far corner - past goalkeeper Conor O'Malley - by Argyle target man Ryan Taylor.Plymouth's Portuguese playmaker Ruben Lameiras' measured shot was deflected on to the post and out for a corner after 48 minutes.Peterborough were reduced to 10 men in the 75th-minute when right back Liam Shephard was shown a straight red card for violent conduct.At the death, the Posh, who were already down to 10 men, had Steven Taylor dismissed for a second bookable offence as he tried delaying Carey's spot-kick which was awarded for a foul on full-back Oscar Threlkeld.