Pompey followed their best result of the season with their worst after losing their unbeaten away record to Gillingham yestreday despite dominating large periods of the match.
The cynics might have seen this result coming after such a great win on Saturday but even they would have had to have been clairvoyants to see such a result coming if they had watched the game, especially in the first half.
Kenny Jackett's men played some good football as they carved the Gillingham defence open, with both Gareth Evans and Oli Hawkins going close. The Gills goal was being peppered with shots but there was always someone to get in the way and on occasion the final ball wasn't quite good enough.
Hawkins was guilty of missing numerous chances during the game and wasted two more headers in the first half which he should have at least hit the target with, then had another cleared off the line by Barry Fuller.
The hosts had barely mustered a noteworthy attempt on goal but took the lead just before the break with a simple goal. Josh Parker got away from Lee Brown when running into the box to head in a cross out wide to give Gillingham the lead well against the run of play.
The second half was a more even affair but Pompey still had the better of it. Another goalmouth scramble was frantically cleared by Gillingham before nobody got on the end of a teasing Ben Thompson ball across goal.
Hawkins then let another excellent chance pass him by as he headed Ronan Curtis' cross wide before being withdrawn for Brett Pitman. Andre Green and David Wheeler soon followed as Pompey played with an entirely new front three in search of an equaliser.
However, Nathan Thompson soon pulled up after running down the pitch and had to be helped off with a hamstring injury which is likely to keep him out until February. It was at that moment that those in the seats on the scaffolding at the Priestfield Stadium believed that it wasn't going to be their day.
That feeling grew as Pitman struck a tame shot at the Gills goalkeeper and there seemed to be no way through the home defence despite the efforts of the ten men of Portsmouth.
All hope was ended in stoppage time when Gillingham were awarded a soft penalty when Jack Whatmough supposedly fouled Elliott List in the box and Callum Reilly dispatched the penalty to confirm a double over Pompey for Steve Lovell to celebrate.
The performance as a whole can't be faulted too much but Pompey were made to pay for their profligacy in front of goal. Hawkins squandered a hat-trick of decent chances whilst Curtis and Lowe started brightly but faded in the second half as both cut frustrated figures.
As much as people want to talk about Pompey's squad strength, the three substitutes had little impact when they came on and now Anton Walkes will be trusted with keeping things steady at right back in Nathan Thompson's absence.
It's clear that Pompey require another striker in the January transfer window. Not just for the rest of this season, but for the future too. Rumour has it that former loanee Jayden Stockley could make a return after supposedly playing his last game for Exeter yesterday, whilst there has also been mutterings of an audacious loan bid for Peter Crouch.
It's likely that this is all a load of rubbish but the squad will have to be strengthened further in January even with the confirmation of Andy Cannon's arrival from Rochdale because the lead at the top of the table has been cut to a single point following Luton's win at Scunthorpe.
Sunderland also won but Bradford fans are saying that they had a clear goal disallowed and a strong shout for a penalty, too. The Black Cats' next fixture looks like a straightforward home win against Shrewsbury whilst Luton have a trickier assignment at Walsall.
Pompey's final match of 2018 is a trip to Fleetwood and if they can repeat yesterday's performance but be more clinical then victory should be the final result and get the promotion bid back on track.
However, should Portsmouth fail to win promotion this season, then being doubled by a poor Gillingham team will be a significant reason why.
Pompey Player Ratings
Craig MacGillivray: 6 - A spectator for most of the game.
Nathan Thompson: 7 - Solid until his injury.
Matt Clarke: 6 - Average by his standards.
Jack Whatmough: 6 - Unlucky to give away the spot kick.
Lee Brown: 6 - General performance was fine but shoulders the blame for the opening goal.
Ben Thompson: 6 - Tried to make things happen.
Tom Naylor: 5 - Needs passing practice.
Jamal Lowe: 6 - Started brightly but struggled in the second half.
Gareth Evans: 6 - Couldn't score despite trying.
Ronan Curtis: 6 - Got more frustrated as the game went on.
Oli Hawkins: 4 - Missed a plethora of chances.
Andre Green (Lowe 69): 5 - Had no impact.
David Wheeler (Curtis 69): 5 - Ditto Green.
Brett Pitman (Hawkins 59): 5 - Wasted the one big chance he had.