Pompey snatched a draw from the jaws of victory after suffering a late collapse against Coventry.
Jorday Hiwula had given the visitors an early lead at Fratton Park, only for goals from Ronan Curtis, John Marquis and Gareth Evans to switch the contest on its head.
But Matt Godden's penalty and a Michael Rose strike secured an unlikely point for the Sky Blues, who had both Fankaty Dabo and Gervane Kastaneer sent off.