Portsmouth 1 Carlisle United 0: Conor Shaughnessy's 93rd minute header handed Carlisle an agonising defeat at the home of the League One leaders.

The Blues seemed on course at least for a point at Fratton Park, and had come close to a winner themselves.

But defender Shaughnessy found space in the box to convert a Jack Sparkes' cross to crush the Cumbrians.

It saw the home side retain their unbeaten start to the season while United - backed by 676 impressively vocal fans on the south coast - remained 20th.

It could have been so much better for the Blues, who gave Pompey plenty of concerns in the second half with Alfie McCalmont hitting the post before sub Dan Butterworth was denied by a Will Norris save in the 90th minute.

Portsmouth's Colby Bishop missed a first-half sitter but Carlisle increasingly kept John Mousinho's men at bay - until the dramatic late scenes.

News and Star: United are crestfallen after the late goalUnited are crestfallen after the late goal (Image: Barbara Abbott)

United boss Paul Simpson kept faith with the same XI that had started in last weekend's defeat to Leyton Orient, though there were a couple of changes on the bench.

Young keeper Gabe Breeze stepped up with Jokull Andresson out with illness, while Butterworth took Corey Whelan's place among the subs.

Pompey made three changes, handing starts to Tino Anjorin, Alex Robertson and Regan Poole as Sean Raggett, Christian Saydee and Ben Stevenson dropped to the bench.

Carlisle, watched by would-be owners Tom snr and Patty Piatak at Fratton Park, began competitively and forced the first serious opening when Owen Moxon dribbled into the box from the left only to be denied at the near post.

The home side then flexed their muscles and applied some sustained spells of pressure, Anjorin curling wide from 25 yards and Robertson volleying straight at Tomas Holy after a strong attack.

Bishop then passed up two headed opportunities before United broke and a Jack Armer cross found McCalmont at the far post, but he couldn't beat keeper Norris when well placed.

After a solid United spell midway through the half, with Joe Garner leading the line well and Fin Back proving a bright outlet on the right, Paddy Lane and the dangerous Abu Kamara then failed to make the most of more Pompey opportunities as they ran beyond Simpson's defence.

News and Star: Owen Moxon on the ball at PortsmouthOwen Moxon on the ball at Portsmouth (Image: Barbara Abbott)

Bishop then squandered the best chance so far, volleying Sparkes' cross wide when a goal seemed certain.

United were living on a knife-edge at times, with Lane and Bishop unable to convert after an Anjorin run had opened Carlisle up, and the Blues reaching half-time intact after Anjorin fired a final attempt into orbit.

Simpson's side then started the second half brightly and could easily have taken the lead.

In the first minute after the restart they found McCalmont in space in the box but his shot came back off the post.

Sean Maguire then ran at the hosts through the middle and forced a block, while Sam Lavelle was denied at the near post following a Moxon corner.

United contained another spell of home pressure before Moxon drilled wide from outside the box following a Jordan Gibson break.

News and Star: Jordan Gibson battles with Regan PooleJordan Gibson battles with Regan Poole (Image: Barbara Abbott)

Carlisle did well to limit Portsmouth chances even though sub Saydee and Kamara almost combined to open something up on the left.

Simpson then sent on Butterworth for McCalmont as United remained very much in things, attacking the away end full of vocal travelling fans, who barely stopped singing all game.

Garner, who was booked for a foul and received a talking-to by ref Leigh Doughty after another challenge, was replaced by Luke Plange, before Gibson fired two attempts off target as United continued taking the game to their high-flying hosts.

Jack Robinson was next on for the Blues, in place of Guy in midfield for the closing stages, as Butterworth came agonisingly close to a 90th minute winner when his low first-time effort was touched around the post by Norris.

News and Star: Celebrations on Portsmouth's bench after the winning goalCelebrations on Portsmouth's bench after the winning goal (Image: Barbara Abbott)

Carlisle, having come close to a winner, then looked set to defend their way to a point, then conceded in cruel fashion right at the death.

Pompey forced a corner and, from Sparkes' inswinging delivery, Shaughnessy found space to rise and head low into the Blues' net.

The home fans erupted and United's hopes of a valiant result at Fratton Park were crushed.

Portsmouth: Norris, Poole, Rafferty, Shaughnessy, Sparkes, Robertson (Raggett 90), Morrell, Kamara, Lane (Yengi 78), Anjorin (Saydee 58), Bishop. Not used: Schofield, Ogilvie, Stevenson, Devlin.

Goal: Shaughnessy 90.

Booked: Rafferty.

United: Holy, Back, Armer, Lavelle, Mellish, Guy (Robinson 83), Moxon, McCalmont (Butterworth 68), Gibson, Maguire, Garner (Plange 78). Not used: Breeze, Edmondson, Ablade, Barclay.

Booked: McCalmont, Guy, Garner.

Ref: Leigh Doughty.

Crowd: 17,911 (676 United fans).