Sunderland 1-2 Portsmouth Highlights
Jermain Defoe crashed in an injury-time penalty to secure a first victory for new Portsmouth manager Tony Adams.
Djibril Cisse gave Sunderland the lead after just three minutes after being set free by Andy Reid, but the striker then wasted a succession of chances.
David James denied him three times, while Kieron Richardson hit the post.
Nadir Belhadj then struck from 35 yards after the break to level and, after El-Hadji Diouf fouled Glen Johnson, Defoe earned a real smash-and-grab win.
It was Sunderland’s third straight defeat in the league and leaves boss Roy Keane’s side just a point off the drop zone.
But it could – and should – have been a different story for Sunderland who had enough chances to win the game comfortably against a Portsmouth side that had lost their previous two games since Adams took over from Harry Redknapp.
After their 5-0 mauling to Chelsea last time out, Sunderland had the perfect start when Cisse threaded the ball through James’s legs following Reid’s searching 60-yard pass over the top of the defence.