They’ve also faced Sunderland and Charlton – two teams tipped to be in the running for promotion before the season got under way – with their record in these keys games reading P6 W4 D0 L2.
That’s s decent effort, with 12 points out of a possible 18 secured.
But who has been Pompey’s go-to man or players for the big occasion.
Well, we’ve went through each game and checked our match ratings to assess who’s hot and who’s not so hot when it comes to these crunch clashes.
Here’s what we found…
Note: Only those who have played in more than half the games have been included.
5. Sean Raggett - 7.3 match average
Has a 100-per-cent presence in these games - and it's understandable why given his influence at the back. Photo: JPIMedia
6. Marcus Harness - 7.2 average rating
Was the star man against Sunderland at the Stadium of Light, with his opener there setting the tone. That's been his only goal against the Blues' promotion rivals but still has a big influence on these games. Photo: JPIMedia
7. Craig MacGillivray - 7 average rating
The keeper has two clean sheets to his name from these key battles. Has conceded five goals in total, but can be relied upon to come up with the goods when tested. Photo: JPIMedia
8. Callum Johnson - 6.8 average rating
Has played in all six so-called big games to date - and just like his overall form, the full-back rarely lets you down. A rating of six against Charlton his only negative. Photo: JPIMedia