Pompey lost 2-0 to Bristol Rovers to leave Richie Barker still waiting for his first win as manager.
Goals in each half from Ollie Clarke and David Clarkson made it two defeats from two for the new Blues boss.
More worringly, it left Pompey without a win in nine outings as they continue to move in the wrong direction towards the relegation zone.
There were signs that woeful record may be halted as the visitors made an encouraging start to the game at the Memorial Ground.
Jed Wallace’s eighth-minute strike forced a good save from Rovers keeper Steve Mildenhall and quickly hushed a vocal home support.
Clarkson smacked the woodwork nine minutes later with a tremendous strike that sailed over Trevor Carson’s outstretched arm.
But once again, it was Pompey who made the early running.
Wallace was again denied by Mildenhall before Ryan Bird was denied by the keeper’s legs.
All that good work was cancelled out, though, on 39 minutes when Clarke’s first-time effort from 25 yards flew past Carson and into the back of the net to give the Gas a lead they hardly deserved.
The home side could have added to that goal but Tom Parkes headed over when unmarked two minutes before half-time.
But with Rovers coming out for the second half buoyed by their advantage, they continued to have the upper hand over a Pompey side clearly lacking in confidence.
A second goal looked likely when Clarkson and then Richards were denied by Carson as Rovers upped the pressure.
And that strike came on 77 minutes when Clarkson let fly with a superb right-foot shot from the edge of the area.
Pompey replied with a Wallace effort that Mildenhall had to tip over the bar for a corner.
But that was all the 1,355 travelling Pompey fans had to cheer after half-time as the Blues suffered their seventh defeat in nine games.