Pompey fell to their third league defeat of the season in a breathless 3-2 Boxing Day defeat at Leyton Orient.
Two goals from former Hawks striker Ollie Palmer proved crucial as both sides were reduced to 10 men at Brisbane Road.
Paul Cook’s side were dominant early on before Adam Webster’s dismissal changed the face of the game.
They fell 2-1 down at the interval and then went further behind after Orient skipper Mathieu Baudry was sent off.
The Blues rallied and pulled a goal back through Evans, but their late charge failed to deliver a return.
And they will reflect on giving away the impetus in game they had control of.
The afternoon couldn’t have started any better for Pompey as they took the lead after four minutes.
It was Kyle Bennett who put the dangerous ball in. Gareth Evans got a faint touch before Connor Essam diverted the ball past Alex Cisak.
Pompey were on top and dominating, but that changed as Adam Webster was sent off as Jay Simpson levelled from the spot after 23 minutes.
Danny Hollands appeared to aim a pass at Brian Murphy, but Webster tried to take control before losing out to Jobi McAnuff - and the pair then fell to the turf in a untidy heap.
Referee Graham Norwood had no hesitation in pointing to the spot and sending off Webster - before Simpson dispatched the spot kick.
That set the pattern for the rest of the half with Pompey under pressure and Adam Barton operating as a makeshift central defender.
They made it to stoppage time before conceding a poor, poor second.
It was former Pompey loaneee Cole Kpekawa who angled a long, hopeful ball in from his own half.
Brian Murphy eventually chose not to come and collect and Palmer easily headed home in front of Matt Clarke.
The game sprung to life again seven minutes after the restart as Orient were reduced to 10 men.
Captain Baudry was dismissed after planting his head into the face of Pompey captain Michael Doyle,.
But, as Pompey sensed a way back into the game, they went further behind moments later as Palmer was allowed to head home a free-kick unopposed.
It was a dagger blow but Evans was then denied a goal as Cisak pulled off another top-drawer save to keep out his header.
Pompey did pull a goal back after 66 minutes, though, as Bennett freed Evans with a peach of a pass and the winger coolly slotted past Cisak.
That paved the way for incessant Pompey pressure, with Davies having a shot well saved and then Evans firing a great chance over the top after 71 minutes.
Gary Roberts made his injury return late on as the Blues chased the leveller through seven minutes of stoppage time.
And there was another fine save from Cisak at the death to deny Evans and send Pompey to defeat.