Swindon took the lead against a strong Pompey side after Noe Pamarot and Sol Campbell gave away a soft penalty that striker Simon Cox was supposedly looking for. Cox tucked the ball past David James to give the hosts the lead.
It took Pompey a long time to get into the game but eventually they woke up and Hermann Hreidarsson equalised after playing a neat one-two with trialist O.J who was given another game.
Pompey then took control and the impressive O.J was fouled in the box which allowed Jermain Defoe to score his second pre-season spot kick.
Changes were made at half-time as Peter Crouch made his second debut in a Pompey shirt whilst Sylvain Distin and Ben Sahar were amongst those coming on.
Asmir Begovic was called into action as Distin almost put through his own net but the game died down until Billy Paynter missed a sitter for the Robins. The game then died down as the usual mass substitutes were made.
Anthony McNamee was very impressive for Swindon and caused many problems for the Pompey defence but it was Pompey who struck in the last minute as Danijel Subotic headed in a Ben Sahar cross.