Pompey have been relegated from the Championship after a 2-1 defeat to Derby.
The Blues needed to win at Fratton Park to stand any chance of taking their battle for survival to the final weekend of the season.
But goals from Jake Buxton and a Steve Davies penalty, which came either side of a Luke Varney leveller, condemned Michael Appleton’s men to League One.
Even if Pompey had won, they still would have suffered the drop after Bristol City saw off Barnsley at Ashton Gate to seal their survival and also send down Coventry.
Buxton’s free header from Jamie ward’s corner opened the scoring after 41 minutes.
Varney then made no mistake after breaking the offside trap from Marko Futacs’ through ball on 74 minutes.
Hope of a result was short-lived, though, when Ward went to ground under Jason Pearce’s attention four minutes later for a disputed penalty, which Davies netted from.
Pompey fans remained defiant at full-time, with the players returning to the pitch to salute their fans.
Pearce was named The News/Sports Mail player of the season before the game.