View the photos from the Blues' League One success at Spotland
Pompey returned to the top of the table after fighting from behind to win 3-1 at Rochdale.
They fell behind to Aaron Wilnbraham's unstoppable long-range effort, but failed to let that setback sap their confidence.
Jamal Lowe slid home the equaliser, while skipper Brett Pitman turned the match on its head in the second half.
And a fine finish from defender Matt Clarke late on secured another victory for the unbeaten Blues.