Steve Claridge scored the fastest goal of the day to set Portsmouth up for a well-earned victory against fellow strugglers Crewe.
But it took strikes from Thomas Thogersen and Kevin Harper to seal the points after Crewe had fought back through a second-half Colin Cram equaliser.
Thogersen collected a loose ball as Crewe cleared a 62nd-minute corner and his deflected strike wrongfooted keeper Jason Kearton as it flew through the pack of Alex defenders.
And Harper killed Crewe off on 86 minutes as he headed home a Justin Edinburgh cross.
The two goals were the perfect answer to a Crewe side who had moved up a gear after Cram had finished off a neat one-two with Mark Rivers on 57 minutes to cancel out Claridge's early strike.
Portsmouth marked their attacking intentions clearly from the start and were rewarded on three minutes when Claridge sidefooted home Ceri Hughes' low drive from three yards after a clever step over from Lee Bradbury.
Hungry Portsmouth nearly doubled their advantage seconds later when a similar move put Claridge in on goal but Steve Wright's last ditch block forced the Pompey veteran's shot onto the bar.
Pompey continued to fashion openings and on 10 minutes Harper just failed to find Claridge as he looked in a dangerous position to score.
Rivers sent Rodney Jack racing clear on the right. The front man beat Darren Moore for pace but steered his cross into the hands of keeper Russell Hoult as Rivers waited in the box.
Moore then flashed a header over the Crewe goal from a Claridge corner.
Kenny Lunt went close to grabbing an early equaliser for the Railwaymen with a fierce 30-yard shot that whistled inches wide of Hoult's goalmouth.
As the first half progressed Portsmouth relented, allowing Crewe to settle into their trademark passing game.
But all too often they could have been accused of over-elaboration, Jack skewering only their second first-half shot into the stand from the edge of the box.
An ill-tempered second half boiled over on 50 minutes when Thogersen's ugly challenge on Jack resulted in an angry confrontation between the two teams.
Two minutes later Shaun Derry marked his Portsmouth debut by joining first-half offender Edinburgh in the book for dissent.
Pompey nearly put the game beyond Crewe at an earlier stage when Harper caused havoc in the home side's box leaving David Wright for dead before whipping in an inviting cross which Claridge just failed to meet at the far post.
Harper then flashed a thunderbolt wide at the death as Crewe offered little in return.