Pompey will face Sunderland in the Sky Bet League One play-offs after finishing fourth in the table.
The away leg will take place at the Stadium of Light on Saturday, May 11 (7.30pm kick-off), with the Fratton Park fixture to be played on Thursday, May 16 (7.45pm kick-off).
Tickets for the home match have now sold out.
Seats are still on general sale for the away leg. Click here for details on how to secure your seat.