A first-half horror show proved costly as Morecambe slumped to their second defeat of the season at Fratton Park.
The Shrimps were three goals down at the break and a man down after Andy Wright’s sending off.
After a solid opening they conceded their first goal on 20 minutes after a neat Portsmouth move.
The home side exchanged passes on the edge of the Morecambe box and played in Jed Wallace who made no mistake with a cool finish past Andreas Arestidou.
The Shrimps hit back and were denied a good penalty claim when Padraig Amond’s right wing cross looked to hit the arm of Joe Devera.
The referee only gave a corner and to rub salt into Morecambe’s wounds the home side added a second with a swift breakaway.
Andy Parrish was left as the only Morecambe defender as Portsmouth broke and although he got in an initial challenge the ball fell to David Connolly who scored his third of the season from close range.
Morecambe’s frustrations boiled over on 36 minutes when Andy Wright was sent off for a second yellow card after a poor tackle on Andy Bircham and the 10 men went a further goal down three minutes later when with the Shrimps all at sea Patrick Agyemang scored from acute angle with a shot that went in off the post.
Jim Bentley’s side looked much more solid in the second half and went closest to scoring the game’s next goal when Tony Diagne’s long-range shot was spilled by Phil Smith and Ryan Williams went close with two efforts from distance.
They failed to score for the second time in three games however and were left with plenty to think about after a shocking first 45 minutes.
Portsmouth: Smith, Moutaouakil (Holmes 66), Devera, Bradley, Painter, Wallace, Ferry (East 55), Padovani, Barcham, Connolly, Agyemang (Craddock 77). Subs not used: Sullivan, N’Gala, Bird, Butler.
Morecambe: Arestidou, Hughes, Parrish, Diagne, Wright, Drummond, Fleming, Williams, Threlfall, Amond (Kenyon 46), Sampson (Mwasile 81). Subs not used: Roche, Ellison, Marshall, McGee, Doyle.
Referee: D Drysdale.