Abu Kamara’s fine strike ensured Pompey returned to winning ways with a controlled performance at Fleetwood.
The forward's goal separated the sides after a first half that saw very few chances, but the Blues dominant throughout.
It was a more open affair following the interval, although the visitors dealt with some late pressure from the League One strugglers to take all three points back to the south coast.
John Mousinho made three changes from the side that were beaten by Leyton Orient on home soil the previous week.
Tom Lowery and Ryley Towler were both handed their first league starts since the opening day, while there were also a return for Terry Devlin.
Joe Rafferty, Jack Sparkes and Christian Saydee were the men to make way, as Pompey switched to three at the back.
The visitors looked in control from the very start, but despite dominating possession, they were unable to fashion any early chances.
It was difficult on a bobbly surface, although the Blues were doing their best to pass the ball around in search of openings.
There was a teasing cross delivered into the box from wide on the left by Paddy Lane, which Kamara could not quite get on the end of.
It was a similar story when fellow wing-back Devlin sent the ball in from the opposite flank and again a grey-shirted player was unable to make a connection.
But the Blues did break the deadlock on 25 minutes after Marlon Pack had threaded a neat pass through to KAMARA.
He beat both Josh Earl and Josh Vela before firing in a fierce 20-yard shot that was too powerful for Jay Lynch to keep out.
Kamara then did well to steal possession from Ben Henghan inside the area, but the defender was able to shepherd the ball out of play.
Colby Bishop was next to go close, seeing a low effort deflected past the post after Lane and Kamara had combined to find the striker.
There was nothing to concern Will Norris at the other end of the pitch, with Fleetwood unable to maintain any prolonged periods of possession.
And it might have got worse for the hosts just before the break, as after a spot of pinball in the area, Lane saw his shot blocked.
Half Time: Fleetwood 0 Pompey 1
There was a change at the break, with Joe Morrell – who had earlier been on the end of a late challenge and also got booked – replaced by Saydee.
It took just a few seconds of the restart for the hosts to threaten for the first time, as former Fratton loanee Jayden Stockley diverted Bosun Lawal’s shot just past the post.
Pompey soon had a chance of their own and Lynch spilled Pack’s long-range attempt, but was able to gather the ball at the second attempt.
They went even closer moments later and Lynch did well to deny Bishop from point-blank range after Pack and Saydee had helped the ball into his path following good work from Kamara on the right.
The Cod Army had an opportunity of their own on 67 minutes, when a clearance from Conor Shaughnessy ricocheted off Danny Mayor and flew just wide.
Norris then came to the rescue, with a smart stop to deny Brendan Wiredu, as the hosts began to show more urgency.
Fleetwood were certainly posing more of a threat, even if Pompey were still looking relatively comfortable.
Sparkes was brought on for the lively Kamara, as Mousinho looked to shore things up for the closing stages.
And there was also a welcome return for Connor Ogilvie after a long injury lay-off, as he replaced Lowery on 84 minutes.
It was Pompey who looked more likely to score again as the game entered stoppage-time, but one goal was enough to seal the win.
Fleetwood (3-4-3): Lynch; Wiredu, Heneghan, Earl; Vela (c), Lawal, Dolan (Johnston 21), Boyes; Marriott (Omochere 60), Stockley (Patterson 77), Mayor (Coughlan 77)
Booked: Vela, Heneghan, Lawal, Marriott
Subs not used: McMullan, Rooney, Holgate
Pompey (3-4-2-1): Norris; Shaughnessy, Raggett, Towler; Devlin, Pack (c), Morrell (Saydee 46), Lane; Kamara (Sparkes 80), Lowery (Ogilvie 84); Bishop
Goals: Kamara 25
Booked: Morrell, Shaughnessy, Pack, Lane
Subs not used: Macey, Martin, Whyte, Scully
Referee: Neil Hair
Attendance: 3,782 (1,100 Pompey fans)