Goals from Marcus Harness, Freddie Ladapo and Wes Burns saw Town to a dramatic 3-2 victory over previously unbeaten Portsmouth, who had twice levelled from the penalty spot, at Portman Road. Harness netted against his old club on 25 but Colby Bishop converted the first of two spot-kicks for Pompey seven minutes later. In the second half the game was settled after three goals in seven minutes, sub Ladapo put the Blues back in front in the 74th minute with his first touch but Bishop again equalised from the spot on 79, however, straight from the kick-off Town, who remain second in the table, won it through Burns.
The Welshman and Tyreece John-Jules returned to the line-up for Kayden Jackson and Ladapo, who dropped to the bench.
Burns, who missed the trip to Plymouth having been away on international duty with Wales, came in wide on the right, while John-Jules was the lone central striker with ex-Pompey pair Harness and Conor Chaplin behind him.
For Portsmouth, Ipswich-born Joe Morrell came into the midfield for Tom Lowery, who has had a hamstring injury, while former Town loanee Ryan Tunnicliffe was on the bench and on-loan Blues frontman Joe Pigott was ineligible.
Town started the game positively, controlling the game with Portsmouth unable to get on the ball.
The Blues created their first chance in the eighth minute, Burns cutting back from the right to Chaplin but the former Pompey man scuffed his shot.
Within a minute, Harness sent Leif Davis away on the left and his cross found Burns deep on the right but his shot was blocked.
Following the corner, the Blues went close again, Davis cutting back from the left and John-Jules trying to turn the ball goalwards from behind him. It looked to be going wide before hitting a couple of defenders and going behind.
From that flag-kick Town again almost went in front, Chaplin hitting a shot on the turn against the post after a loose ball had fallen to him.
The Blues maintained the pressure and in the 11th minute Dane Scarlett was shown the game’s first yellow card for a late challenge on George Edmundson midway inside the Portsmouth half to the right.
In the wake of Lee Evans’s free-kick, Chaplin, making his 50th league appearance for the club, crossed from the left and Edmundson’s looping header was claimed under the bar by visitors keeper Josh Griffiths.
Portsmouth saw a bit more of the ball in Town’s half as the game approached the 20-minute mark but Scarlett’s hopeful effort from distance was miles away from Christian Walton’s goal.
In the 22nd minute, a Pompey free-kick from the right was punched to the edge of the area by Walton from where Josh Koroma hit a shot against Janoi Donacien, then a subsequent effort was blazed well over.
Town attacked from the free-kick, John-Jules seeing a shot blocked, then the ball looped out to the left of the box from where Davis hit an effort which deflected over Griffiths but onto the roof of the net. From the corner, Edmundson headed over.
The Blues had had more than a few chances and in the 25th minute they made one count, and perhaps inevitably both Town’s former Pompey players were involved.
John-Jules tussled with Morrell on halfway and the ball fell to Chaplin, who brought it forward before playing in Harness, who confidently slipped his sixth goal of the season past the advancing Griffiths and into the net before celebrating in front of the Sir Alf Ramsey Stand and not too far away from his old fans.
But six minutes after the Blues went in front, Portsmouth were awarded a penalty. Luke Woolfenden allowed Scarlett to get behind him as the ball was played into the right of the box and Walton upended the on-loan Tottenham forward. Referee Charles Breakspear pointed straight to the spot and yellow-carded the Town keeper.
Colby Bishop took the penalty and hit it low to Walton’s right and the ball just made it under the keeper who will have been frustrated not to have saved it.
Town went about restoring their lead and in the 36th minute skipper Sam Morsy curled a shot over from the edge of the box.
Two minutes later, Burns took down Evans’s deftly-weighted ball over the top and John-Jules played it into the path of Chaplin, whose effort was scraped wide.
On 44, Davis played a pass from deep on the left to Chaplin in the centre circle where the forward took it down superbly before playing an equally impressive ball into the path of Burns on the right. The Welshman took it on to the edge of the area before hitting a shot which Griffiths batted away. From the corner, Harness’s stooped header was easy for the keeper.
Just before half-time, Chaplin looked to be tripped in the area but remained on his feet and despite Town protests, referee Breakspear wasn’t interested.
Town will feel they had done enough to go in ahead at the break, Chaplin and Harness having done brilliantly to create the opening goal and the Blues having created plenty of other opportunities.
But as so often over the last couple of weeks, Town were made to rue a defensive error which allowed Pompey back into the match.
Town had been more subdued immediately after conceding but had begun to look more threatening close to half-time.
The visitors forced the first save of the second half, Marlon Pack hitting a powerful 25-yard free-kick which Walton punched away, the ball appearing to have moved late in the air.
Town were next to threaten, John-Jules turning a shot over from Chaplin’s hooked ball in from the left.
Blues left-back Davis and Pompey’s Conor Ogilvie both underwent treatment as the game hit the hour mark following a collision midway inside the Town half. Davis looked to have hurt his knee, while the Portsmouth player initially appeared to be holding his head. Both were OK to carry on.
What had been an enthralling game in the first half was drifting rather in the second, n part due to niggly fouls and stoppages. On 66 Portsmouth made the first substitutions, Ronan Curtis and Tunnicliffe replacing Koroma and Morrell.
Four minutes later, Owen Dale somehow got away without being booked for a foul on Burns much to the annoyance of the Town support having previously made a very late challenge on Davis among a number of other poor tackles.
Town’s performance had become flat and in the 73rd minute manager Kieran McKenna made some much-needed changes, Kyle Edwards taking over from Harness and Ladapo from John-Jules.
And within a minute, Ladapo had restored the Blues’ lead with his first touch of the ball. Davis cut the ball back from the left and the striker brilliantly turned a first-time strike into the top corner of the net. Ladapo delightedly celebrated his four goal of the season, his third in three games and his second in the league in successive weeks.
But again Town’s lead didn’t last with Pompey once more levelling from the penalty spot five minutes later.
This time Morsy and Curtis tangled just inside the box and referee Breakspear pointed to the spot. On this occasion Bishop hit his spot-kick to Walton’s left with the keeper diving to his right.
However, Town restored their lead for the second time straight from the kick-off. Edwards made a direct run down the left, his cross caught a defender and looped over Griffiths and Burns headed his second goal of the season into the roof of the net from under the bar before celebrating in front of the ecstatic North Stand.
Having got their noses back in front, the Blues swapped Chaplin for Dominic Ball, then on 85 Pompey skipper Clark Robertson was yellow-carded for a foul on Morsy. Two minutes later, the visitors switched Michael Morrison for Reeco Hackett.
In the 88th minute, Edwards and Ladapo exchanged passes on the left before the ex-West Brom man struck a shot which was deflected behind. Soon after, one-time Blues target Michael Jacobs replaced the fortunate-not-to-be-booked Dale.
Davis went looking for a fourth goal to settle the game but his chipped effort from the left towards the far top corner looped just wide.
Deep in seven minutes of injury time Davis was replaced by Kane Vincent-Young with the Blues seeing the final moments out reasonably comfortably if with Portsmouth seeing most of the ball, although with their progress hampered by Blues fans holding onto it at restarts.
Referee Breakspear’s whistle sent Portman Road into raptures, the Blues having secured an important victory after claimed only a point from the trips to Sheffield Wednesday and Plymouth having been in winning positions against both.
With the second half drifting, Town needed to make changes to regain the impetus and the switches of personnel made by manager McKenna certainly worked with Ladapo netting an excellent goal after coming on.
Portsmouth’s second penalty - their goals were their only shots on target all afternoon - looked like a tangle of legs more than a foul but the Blues responded brilliantly to conceding for a second time with Edwards instrumental in creating the winner.
From there, Town saw out the final minutes without any severe concerns to claim a rare victory over a side towards the top of League One.
Plymouth’s 1-0 win at Wycombe sees the Pilgrims stay top a point ahead of the Blues with Portsmouth now fourth behind Sheffield Wednesday, who are a point behind Town. The Blues are in action again at home to Cambridge United on Tuesday evening.
Town: Walton, Donacien, Woolfenden, Edmundson, Burns, Evans, Morsy (c), Davis (Vincent-Young 90), Chaplin (Ball 82), Harness (Edwards 73), John-Jules (Ladapo 73). Unused: Hladky, Keogh, Jackson.
Portsmouth: Griffiths, Robertson (c), Ogilvie, Pack, Bishop, Dale, Morrell (Tunnicliffe 66), Scarlett, Raggett, Koroma (Curtis 66), Morrison (Hackett 87). Unused: Oluwayemi, Swanson, Tunnicliffe, Curtis, Mingi. Referee: Charles Breakspear (Surrey). Att: 28,434 (Portsmouth: 1,941).