At 2-0 after 79 minutes, the Blues looked out of it until substitute Reeco Hackett pulled one back and threatened to inspire a remarkable late comfortable.
However, in stoppage time, Plymouth hit the visitors on the break to seal their victory and a return to the top of the table, yet there were some positive Pompey performances.
Here are our on-the-whistle player ratings...
17. Reeco Hackett - 7
(Replaced Ryan Tunnicliffe on 68 minutes) Like Peterborough, really positive impact following introduction from the bench. His left-footed strike to make it 2-1 threatened a comeback, but that unfortunately didn't materialise. Photo: National World
20. Ryan Tunnicliffe (8) of Portsmouth leaps in the air to win the ball during the EFL Sky Bet League 1 match between Plymouth Argyle and Portsmouth at Home Park, Plymouth, England on 11 February 2023.
Ryan Tunnicliffe makes an aerial clearance in the second half of Pompey's Home Park defeat. Picture: Graham Hunt/ProSportsImages Photo: Graham Hunt