Norwegian striker Erik Huseklepp scored in the 94th minute to give Portsmouth victory over Ian Holloway's Blackpool.
Blackpool missed opportunities to win the game, with Matt Phillips the main culprit, fluffing two easy chances.
The away side might have gone ahead had Ian Evatt's goalbound shot not struck the hand of defender Jason Pearce.
But the Tangerines were left reeling as Huseklepp scored the winner with a 12-yard volley to give his side their first win in five games.
The Seasiders should have taken the lead early on but Phillips shot straight at goalkeeper Jamie Ashdown after being found by Gary Taylor-Fletcher.
Again, former Wycombe striker Phillips could have put his side in front, but dragged his effort wide of goal.
David Norris was lucky to stay on the pitch in the first half after appearing to elbow Evatt.
In the second half Portsmouth came out the better side and could have gone ahead had it not been for Matt Gilks' smart save from Liam Lawrence.
There was controversy in the 70th minute when Evatt's shot, which was heading goalwards, was blocked by Pearce's hand. However, referee Darren Deadman saw no infringement.
Portsmouth rode their luck but grabbed all three points when Evatt, who was heavily involved throughout the game, mistimed a header and the ball fell into the path of Huseklepp, who fired home, much to the delight of the home fans.