Despite twice taking the lead at White Hart Lane, Southampton's hopes of avoiding relegation were hit in a heavy defeat at Tottenham Hotspur.
Southampton went in front through Jo Tessem, before they were pegged back by a Dean Richards own goal. Tahar El-Khalej restored the visiting team's lead before Spurs responded in emphatic fashion.
Darren Anderton pulled Spurs level for a second time before a Steffan Iverson hat-trick and a brace from Chris Armstrong put the score beyond Saints.
The victory pushed Spurs into sixth with 42 points, while Southampton were 16th on 30 points, four above the bottom three.
Pedro Mendes was the hero at Fratton Park as Portsmouth earned their first league win of the year.
Portsmouth took the lead through the Portuguese midfielder at Fratton Park, but Richard Dunne looked to have grabbed a point for Manchester City when he headed in Joey Barton’s corner with seven minutes remaining.
However, in the third minute of stoppage time, Mendes got his second for Pompey’s first win in eight matches.
It was not enough to lift Portsmouth out of the bottom three. They were 19th, still six points from safety. City dropped to 10th on 40 points.