The clock showed 58 minutes when the travelling contingent produced a rendition of ‘We are going up’.
Clutching a one-goal advantage at the Broadfield Stadium, the 2,300 Pompey fans were understandably upbeat.
Paul Cook’s side were on their way to breaking into the top three for the first time in five months and 10 days.
Following defeat at Blackpool in September, the Fratton faithful had been waiting 163 days to return to the League Two automatic promotion spots.
Last night it happened as the Blues ran out 2-0 winners at Crawley following an excellent team display brimming with heart and desire.
And so three days following that wretched home defeat to Crewe and the accompanying avalanche of criticism, Pompey fans were contemplating promotion.
Following a goalless first half, Eoin Doyle missed a 52nd-minute penalty after Enda Stevens had been felled following a superb run.
From the resulting corner, Kal Naismith’s delivery was headed home by Christian Burgess – and Cook’s troops never looked back.
Kyle Bennett made sure of triumph with a wonderful swerving right-foot shot from outside the area on 71 minutes.
Coupled with a home defeat for second-placed Plymouth Argyle against Blackpool, it was a night of joy for Blues followers as their players did them proud.
Contrasting displays and feelings from Saturday, yet the league table has taken on a far more reassuring look after last night.
Cook made two changes to the side which performed so disappointingly against Crewe.
The absence of Amine Linganzi was expected after Pompey’s boss admitted the midfielder was struggling with fatigue which had left him with a hamstring problem.
The return of Danny Rose to the line-up was therefore a foregone conclusion, with the midfielder making his first start since facing Exeter City in January.
There was also a change in the midfield positions, with Gary Roberts replaced by Carl Baker in the attacking three.
Pompey’s joint-top scorer took his place on the bench following a seven-game run in the starting line-up.
There was also a maiden squad appearance for Stanley Aborah, following his arrival as a free agent last month.
With Rose stepping into the side, the former Notts County man took his place among the substitutes to offer back-up in the holding midfield roles.
Meanwhile, Jack Whatmough was unavailable having picked up a knock, with Tom Davies returning to the bench as defensive cover.
In an energetic start, Pompey won the first corner of the game on eight minutes when Glenn Morris touched Eoin Doyle’s cross behind.
However, Kal Naismith’s corner was a poor one, failing to beat the first man.
Moments later, another Naismith corner, this time from the right, was met with a header from Gareth Evans which glanced wide of the far post.
On 15 minutes, Bennett collected a ball from deep and cut inside from the left past two defenders, yet his shot was comfortably wide.
The visitors were controlling the match and in the 21st minute some patient build-up – with Bennett at the heart of it – saw Rose teed up on the edge of the area.
The midfielder drove in a first-time left-foot shot which flew straight at Morris, who dived forward to gather.
It was Rose who also provided the Blues’ next attempt on goal, taking Bennett’s clever inside pass before curling a left-foot shot which was gathered by the keeper.
Pompey should have taken the lead on 33 minutes when Baker slipped through Eoin Doyle.
The striker held his run to beat the offside trap yet, with only Morris ahead, struck a right-foot shot straight at the keeper.
It was a wonderful moment for the Irishman to net his second Pompey goal but the chance went begging.
Lewis Young became the first player to be booked after he tripped Naismith down Pompey’s right flank.
Crawley then created their best opportunity on 42 minutes when Rhys Murphy sent a right-foot shot from outside the box just past the post, with Pompey keeper David Forde struggling to get across.
With half-time approaching, Baker put an early cross in from the left which was met with a Naismith half-volley into the ground.
It was goalless at the break and shortly after the restart there was a scare when James Collins rolled Burgess before surging forward and firing a fierce angled effort across goal.
The breakthrough arrived on 54 minutes, although only after more Pompey agony.
Enda Stevens earned a penalty following Josh Lelan’s trip inside the box.
The spot-kick was taken by Eoin Doyle, yet the striker’s shot was a poor one.
It was saved low down by Morris before the ball was bundled out for a corner.
Naismith took the set-piece duties down the right and Burgess rose to hand the Blues a 54th-minute lead with a powerful header.
Cook was forced into a substitution on 64 minutes when Stevens went off injured.
Noel Hunt was introduced into the action and Naismith dropped to left-back to cover for Stevens.
The Scot, however, then popped up in attack to whip in a cross which was fed back to Baker, whose goal-bound shot was blocked by Morris.
Pompey increased their lead on 71 minutes through a superb strike from Bennett for his second goal of the season,
Hunt started off the move, nutmegging Lelan down the left.
Bennett picked up the ball, drove forward and then unleashed a right-foot shot from outside the box.
The visitors had their two-goal advantage, although moments later Crawley substitute Billy Clifford saw his first-time shot saved superbly by the legs of Forde.
But Pompey held on and with 11 matches remaining have their hands on third spot with 11 matches to play.