Goals from Greg Halford and Joel Ward gave Michael Appleton his first win in charge of Portsmouth this evening.
Lukas Jutkiewicz equalised for visiting Coventry but his effort was quickly cancelled out by Ward.
Pompey took the lead from the spot after Joe Murphy brought down Ward. Halford stepped up to convert the resulting penalty kick.
Jutkiewicz scored the leveller with a neat finish at the near post nine minutes after the break before Ward's goal just five minutes later.
Andy Thorn's Sky Blues are now bottom of the league while Pompey move up one place to 18th.