Pompey stand five wins away from Championship football.
And Kenny Jackett’s men would have to shatter a club record in order to match that daunting challenge.
As it stands, the Blues are two points adrift of second-placed Barnsley with a game in hand.
Meanwhile, they are scheduled to visit Sunderland on April 27, throwing up a potential automatic promotion decider.
Pompey are League One’s form team, with six-consecutive victories, including a Checkatrade Trophy final triumph over the Black Cats.
Earlier this season, Jackett’s troops equalled the club’s Football League record of eight-successive wins in all competitions.
At this juncture, effectively they require a total of 11-straight victories to claim second spot ahead of Sunderland, Barnsley and Charlton.
That would equate to a tally of 95 points – eight more than the amount which secured the League Two title in 2016-17.
Of course, the current victory target of five is liable to alter, dependent on how the four rivals fare during the remaining run-in.
Notably, the top five have dropped points during the past two matches, including Sunderland (five points), Barnsley (three points) and even leaders Luton Town
In contrast, the Blues have stretched their winning streak to five in the league and six overall.
Earlier this season, they amassed eight-straight victories, from November 3 until December 8, 2018.
That consisted of four League One fixtures and two apiece in the FA Cup and Checkatrade Trophy.
This time around, they require 10 alone in the league – a figure never before achieved in Pompey’s 98-year Football League presence.
The current squad share the existing eight-win record with Harry Redknapp’s Division One-winning side of 2002-03.
From August 17 until September 17, 2002, the Blues collected seven league wins and another in the League Cup, totalling eight-consecutive triumphs.
A return of seven-in-a-row was recorded under Terry Fenwick during the 1996-97 campaign, including the 3-2 FA Cup success at Leeds.
While Bobby Campbell's Division Three winners of 1982-83 amassed seven-straight victories in league action from January 22 until February 26, 1983.
So five wins to go – the Championship and a club record are standing by to mark celebrations.