The rivalry extends to the managers and the dressing room.
Now Pompey will once again lock horns with Plymouth.
Since Paul Cook’s arrival as Blues boss, his side have developed something of a footballing feud with their Devon counterparts.
A last-minute goal from Peter Hartley separated the sides in last year’s League Two play-off semi-final.
It sealed an aggregate 3-2 success for Derek Adams’ side, who would go on to lose against AFC Wimbledon at Wembley.
The 2015-16 campaign also saw Pompey win at Home Park, while the Pilgrims claimed victory at Fratton Park, each decided by a single goal.
This term, Adams’ men secured a 2-2 draw through Connor Smith’s 89th minute leveller in another close encounter.
The sides will do battle tomorrow, with four League Two points separating them.
And Cook is tipping another close affair.
He said: ‘They are always tight games with Plymouth.
‘It is probably two different styles of teams but they are equally adept at trying to be successful.
‘As we speak, Plymouth are four points above us.
‘They’ve had a fantastic year and, in my opinion, will get over the line, without a shadow of a doubt.
‘The reason they will get over the line is because they deserve to.
‘The same as Doncaster.
‘There is a final place for us and winning tomorrow would be a huge boost as a club, making it very difficult for teams to get beyond us.
‘But we have to focus on ourselves – we can’t get carried away.’
Victory for Plymouth would secure their passageway into League One as the season reaches its finale.
Even a draw would suffice, providing Luton and Stevenage both lose in their Good Friday fixtures.
Meanwhile, a Pompey win would cut the gap to one point behind their rivals, putting them in the race for second spot.
Fratton Park is set to be a sell-out for the occasion, after the Pilgrims sold their 2,600 allocation on Monday.
It is expected to surpass the 17,570 opening-day crowd for the 1-1 draw against Carlisle United.
With Sky televising the contest between League Two’s second and third-placed clubs, it will provide a fascinating clash.
And Cook has pledged his players will be fully focused on the challenge.
He added: ‘There is a rivalry that has come from the historical sides of the cities and also probably the way the games have happened.
‘But that is for supporters to get into rather than me.
‘We are very focused on the game and come 2.30pm tomorrow will have done our best to win the game. Once it is over, we’ll prepare them for Notts County.
‘One thing I can assure our fans is we won’t leave a stone unturned in our pursuit of winning against Plymouth.’