A first-half brace from Paul Hayes wasn't enough to prevent defeat in a goal-fest at Fratton Park.Wanderers arrived on the south coast prepared to have a go at in-form Pompey and got off to a dream start when Hayes sidefooted home, only for Christian Burgess and Gary Roberts' penalty to swing the match in the hosts' favour.
Hayes struck again before the break but Conor Chaplin made it 3-2 in first-half stoppage time and Carl Baker's goal early in the second period gave the visitors an uphill task which they couldn't conquer.
Gareth Ainsworth made four changes to the side that lost 4-1 at Luton the previous Saturday, with Southampton loan midfielder Dominic Gape coming into the side for his full debut while Aaron Pierre was recalled to the backline and Garry Thompson and Sam Wood joined the attack.
Sporting their white change shirts with navy shorts and socks, the visitors took up a bold 4-3-3 setup in a bid to halt the title favourites’ recent impressive form, which included comprehensive home wins over Colchester and Crawley.
Danny Rowe was deployed in a man-marking role on dangerman Gary Roberts and the two of them saw plenty of action in a competitive duel early in the game, which restricted Pompey’s chances and left them instead looking to feed the other members of their expensively-assembled frontline.
The first chance fell to Wycombe when the hosts failed to clear the danger and Sam Wood’s low cross-shot was met by Aaron Pierre, but he couldn’t make enough of a connection to bundle the ball over the line and keeper David Forde gathered it in the nick of time.
But the opening goal came moments later courtesy of a stunning cross-field ball from Michael Harriman into the area, which was diverted into the six-yard box with an exquisite first touch from Garry Thompson. Captain Paul Hayes was in the right place at the right time to sidefoot home to stun the hosts and send the travelling fans into raptures.
And with the goal came renewed confidence. Wanderers looked sharp, and organised, with Thompson involved at the other end to track back and make well-timed interceptions to help out his team-mates.
A frustrated Portsmouth side looked to the long ball to get back into the game although a more footballing approach looked their best bet, and once Milan Lalkovic had wriggled his way into a crossing position, Curtis Main’s header was deflected over the bar for a corner.
Action switched to the other end and Wycombe were inches away from a second goal when another superb move involving Hayes and Thompson saw the ball land in the path of the onrushing Sam Wood. The winger threw himself at full-stretch to make contact and saw the ball bounce back off the crossbar before landing in the grateful arms of the keeper.
Portsmouth were forced into a change when Main came off with a head injury, so Conor Chaplin took his place, before brave blocks from Pierre and Anthony Stewart in quick succession prevented Carl Baker from testing Jamal Blackman.
There was more last-ditch defending when Sido Jombati threw himself at a Lalkovic shot, and the same player was then denied by Blackman as the keeper spread himself to prevent an equaliser from a well-worked move.
But the hosts were level on 34 minutes, though it was hardly a classic. A low corner from the right was volleyed goalwards by Baker, forcing Blackman into a save down to his left, and when the ball was lifted back into the danger area, taking a deflection en route, it was bundled over the line amidst a heap of bodies by centre-half Christian Burgess.
Straightaway the Chairboys threatened again when Thompson’s low cross found its way to Hayes, but his first-time shot was scooped at the keeper as he struggled to get it out of his feet in time.
But Pompey completed their first-half turnaround from the penalty spot when Jombati threw himself at Gareth Evans’ goalbound header only for the ball to strike his outstretched arm, and Gary Roberts made no mistake from 12 yards, powering it home into the top corner to give Blackman no chance.
And then Wycombe came back again. Just as four minutes’ stoppage time were signalled, Thompson clipped a bouncing ball superbly into the path of Hayes who almost ripped the net off with a first-time strike into the top corner from 18 yards.
But they were prevented going in all-square at the break by a moment of magic by Conor Chaplin. He met a long diagonal ball with a clever first touch to fend off the challenge from Anthony Stewart – although there were shouts for a handball by Gary Roberts in the build-up - and then, as Blackman came halfway to meet it, cushioned a header over the keeper and into the net to make it 3-2.
The half-time whistle brought an end to an enthralling 49 minutes of football, with the Blues unfortunate to find themselves behind having taken the game to their opponents to take the lead, and then fought back after going 2-1 down. But the late Chaplin goal meant they’d have to do it all over again in the second period.
Paul Cook swapped Milan Lalkovic for Kal Naismith at the interval whereas Wanderers emerged unchanged, and it took only a matter of seconds for Sam Wood to test the keeper with a speculative effort from distance which Forde held.
Anthony Stewart headed wide from Wood’s deep free-kick before the hosts countered and only Gary Roberts will know how he didn’t hit the target with a free header at the back post from Chaplin’s cross.
But another cross was to be Wanderers’ undoing on 53 minutes when Enda Stevens’ delivery was met by Carl Baker, who found it all too easy to hit the back of the net with a first-time effort at the near post.
Pompey had their tails up and were now dominant for the first time in the game, and Naismith should have hit the target when the home side passed their way into a shooting chance, but he curled it over.
Wanderers then got a foothold in the match again but couldn’t threaten keeper Forde despite their high work rate, while the card-happy referee continued his fussiness to dish out numerous cards in what was not a dirty tie. The same official had sent off Marcus Bean harshly at Carlisle last season and been unaware of a rule change regarding GPS devices before the match at Plymouth, and was making no friends here.
Dominic Gape thundered a shot at goal which was deflected just wide by a defender, before the introductions of Dayle Southwell and Adebayo Akinfenwa from the bench gave the visitors hope of changing their approach to force their way back into contention for a share of the points.
But in truth it was Pompey who looked most likely to score next, with Blackman denying Stevens' powerful drive before Baker headed over from a left-wing cross.
Stephen McGinn and Noel Hunt came off the bench for Rowe and Roberts respectively in the closing stages, but there were no further goals as Wanderers succumbed to defeat, although Gape came close to halving the margin of defeat with a last-minute rocket which fizzed just wide.
Wycombe: Blackman, Jombati (Akinfenwa 79), Harriman, Stewart, Pierre, Rowe (McGinn 86), Gape, Bloomfield, Thompson, Wood, Hayes (Southwell 79).
Unused subs: Richardson, Freeman, De Havilland, Kashket.
Portsmouth: Forde, Evans, Stevens, Burgess, Davies, Doyle, Rose, Lalkovic (Naismith 45), Roberts (Hunt 88), Baker, Main (Chaplin 24).
Unused subs: O’Brien, Clarke, Smith, Linganzi.
Referee: Tim Robinson
Attendance: 16,262 (489 from Wycombe)