West Bromwich Albion staged the greatest escape the Premier League has ever witnessed.
But Michael Appleton believes Pompey avoiding relegation would eclipse even that memorable achievement.
On May 15, 2005, the Baggies became the only side in history to stay in the Premier League having been bottom at Christmas.
Bryan Robson’s men pulled off the improbable feat in the 2004-05 campaign, after losing just three of their final 12 matches.
It was a 2-0 triumph over Pompey on the final day which sealed their survival.
In the process it relegated Southampton – much to the delight of both sets of fans at The Hawthorns that day.
Appleton was a coach at West Brom at the time and saw at first hand the achievement.
Now he is attempting to mastermind Pompey’s survival against all the odds.
The Blues lie eight points adrift from safety with 11 matches to go – and star players still being shipped out.
Should he succeed, for Appleton it would rank as one of the finest-ever successes.
He said: ‘This would be more than The Great Escape the sequel, it would be the X-rated version of The Great Escape I would imagine.
‘I remember Bryan (Robson) at the time just saying the pressure was off and he kept repeating that.
‘The players were going into games playing with freedom, knowing that everyone thought they were down anyway.
‘As it panned out, they did ever so well in the last 12 games and stayed up.
‘Going into the last three or four games, especially that last game against Portsmouth, there were so many things that had to go in our favour – and it did. It was amazing.
‘West Brom are the only team to get out of it having been bottom at Christmas.
‘With everything going on at Portsmouth over the past three months, someone recently asked me to put a list together off the top of my head.
‘It was just too easy to roll off the words: embargo, administration, deducted points, losing players, not being paid, deferrals.
‘It is going to take one hell of an effort to stay up, we are not trying to kid anyone. I don’t think anyone is under any illusions.
‘But why not? Why not?
‘West Brom have done it and there are other clubs which have gone on great runs and got out of the mess.
‘It has been done before and it will be done again. So why not?’
Of their remaining 11 matches, five of them are against relegation rivals.
Bristol City are next up, when they visit Fratton Park this weekend.
The Blues also face Coventry (March 24), Millwall (April 10), Doncaster (April 14) and Forest (April 28).
It looks encouraging enough on paper as Pompey attempt to scrap their way up the Championship table.
Appleton, however, is wary of the lack of experience in his Fratton dressing room for the run in.
And that situation is unlikely to improve with the likes of Hayden Mullins expected to be the next to depart.
He added: ‘What I would say is at West Brom you had a dressing room of players who had been in and around that scenario before.
‘I remember Kevin Campbell being at the club at that time and he was fantastic.
‘He never really played much but it was the way he was in and around the dressing room, the training ground, the way he spoke to the players and got around the place.
‘He had this influence – and we need people like that.
‘That is why Liam (Lawrence) will be a big, big miss. He is very influential off the field as well as on it.
‘It is going to be difficult because you need the right sort of characters to get you out of it.
‘We’ve got a bunch of players who I don’t think have ever experienced anything like this, or close to anything like this.
‘It is going to be a new experience for some of them.’