Some 196 days to be precise, coincidentally at Oakwell.
The nights are now drawing in as opposed to getting a bit shorter - and this was most definitely the longest of first-halves for Barnsley, who were dismantled inside eight minutes in a gruesome opening quarter that frazzled minds and saw them concede three goals.
Yes, there was controversy, with referee Lewis Smith infuriating home patrons from the moment he pointed to the spot after deeming that Liam Roberts caught Colby Bishop on eight minutes.
Smith certainly did not have the best of evenings - and incurred the wrath of Neill Collins when he rejected a penalty appeal which saw the Reds chief cautioned.
But what was not open to debate - and something the Lancashire official could not be blamed for - was the way that Barnsley, who looked totally rudderless throughout their midfield and defensive spine in the first half, went to pieces.
Collins had to do something significant at the break and did. The arrival of substitutes Sam Cosgrove, Callum Styles and Owen Dodgson changed the narrative.
Barnsley pulled two goals back - thanks to Barry Cotter and Styles - and the fitful defensive tendencies which had previously afflicted the hosts started to affect Pompey.
They hung on at the end amid a grandstand Reds finale and moved top on goal difference.
Collins's side ultimately left themselves too much to do. Smith won't be welcomed back to Oakwell, that said.
Barnsley were simply atrocious in the first period - although it was disingenuous not to give credit to Pompey, who were fluid and feasted on home anxieties and were excellent. Yet the story surrounded Barnsley’s collapse.
They came into the game on the back of four successive victories and clean sheets. The recent defensive parsimony was obliterated inside 16 bewildering minutes.
They conceded three goals, but the most alarming factor was that it could have been worse. For a former centre-back in Collins, it made for car-crash viewing.
His defenders have received wraps of late. Here, the shadows of Andersen, Kitching and Thomas loomed large.
In the final analysis, Collins's side have played three of League One’s better sides at Oakwell so far this term and been beaten on each occasion - to Peterborough, Oxford and now Pompey.
The tone for a rough night defensively began early for Barnsley. Comfortably before Pompey's breakthrough.
A poor Roberts clearance left the hosts exposed, with only a last-ditch block at the near post from Kacper Lopata denying Gavin Whyte.
Bishop headed over, but the striker - who netted at Oakwell in March - was soon in clover.
Barnsley were opened up down their left and Roberts was adjudged to have caught Bishop following Whyte's cross - with the Pompey top-scorer coolly sending the keeper the wrong way.
Instead of regrouping, Barnsley were dazzled in headlights. Within a minute, Paddy Lane had been sent clear and his curled finish was delicious.
An errant sprinkler sprouting water at the far side of the East Stand added to the sense of pandemonium. There was also no disputing that Barnsley's players were getting a dousing.
Referee Smith was soon on the end of a cascade of abuse, ignoring raucous appeals for a home penalty after Cotter went down in the box.
And then it was 3-0.
Barnsley were again carved open, something Portsmouth were almost doing at will. After Roberts kept out Alex Robertson's low shot, he was soon picking the ball out of his net after Connor Ogilvie was left with the freedom of the box to plant a free header into the box from Joe Morrell's right-wing cross.
Collins's side were stupefied for the rest of the half. He had to change things in major fashion and did with Jon Russell, Nicky Cadden and John McAtee getting the hook.
Mercifully, Barnsley soon looked better and their most convincing move by a country mile ended with the untracked Cotter sliding home his second goal of the campaign after Devante Cole and Cosgrove combined and switched the play nicely.
Bishop, a major pest, then tested Roberts again. Goal king Cole went close, while Cosgrove headed wide at the other end before Styles's meaty header was fumbled by Will Norris following Dodgson's cross and things suddenly became seriously interesting.
Styles' poise and Cosgrove's physicality unhinged Pompey and Dodgson was a good outlet. Cosgrove shanked a chance and Herbie Kane fired wide.
A bit of a bonkers finish ensured and the final whistle was relieving for the visitors, who won for just the second time in 17 trips to this part of South Yorkshire since 1989.
Barnsley: Roberts; Williams, Lopata, McCart; Cotter (O'Keefe 71), Phillips, Kane, Russell (Styles 45), Cadden (Dodgson 45); McAtee (Cosgrove 45), Cole (Watters 78). Unused substitutes: Killip, Shepherd.
Portsmouth: Norris; Rafferty, Poole, Shaughnessy, Ogilvie (Sparkes 69); Pack, Morrell; Robertson (Anjorin 78), Whyte (Kamara 66), Bishop, Lane (Devlin 78); Bishop. Unused substitutes: Schofield, Stevenson, Towler.
Referee: Lewis Smith (Wigan).