On a spinning wicket the home side were forced to dig in during the latter stages of the contest to record an important win.
Home captain Rich Locke praised his troops just a week after slamming them for their weak performance at Hook and Newnham Basics.
A miserable batting performance at Hook had seen them bowled out for just 65 runs and Locke was demanding a reaction.
He was delighted with the response of his team and the way they batted in very difficult conditions.
‘This was a terrific result for us after the lows of the week before,’ said the Portsmouth captain.
‘We showed a lot of character to eke out a win in a very tight game.
‘It was a case of not panicking and showing a bit more belief in our abilities.
‘There is plenty of talent in the team they just have to realise that they can’t always go out and play extravagant cricket.
‘They have to realise there will be times in games when the bowlers will get on top.
‘It is during those times the batsmen have to be prepared to dig in. We did that and showed the guts needed.’
Portsmouth lost the toss but Locke was pleased when Calmore opted to bat first on a wicket that was likely to be lively after the midweek rains.
With both teams boasting strong ‘ spin’ attacks it was always going to be the area that decided the issue.
Opening bowlers Fraser Hay (three for 18) and Reuben McArdle (three for 34) started well but Calmore looked dangerous on 75 for two.
Spinner Andrew Marston (two for 14) helped Portsmouth ensure Sports were bowled out for 121.
‘Andy bowled really well and apart from his wickets only conceded 14 from his 10 overs,’ said Locke.
‘He possesses his father’s competitive spirit.
‘Our attitude in the field was a lot better this week fighting for every run.
‘Though we knocked them over fairly cheaply we knew that it still wasn’t going to be easy because of their spin attack.’
James Christian (21) and Jordan Palmer-Goddard gave Locke’s side the solid start with 42 for the first wicket.
With the fall of a couple of quick wickets memories of the previous weeks collapse came flooding back.
‘The ball was turning a lot and it wasn’t easy to bat,’ said Locke.
Locke (23), though, provided the anchor with an obstinate innings and along with Marston got Portsmouth over the winning line with three balls to spare.
‘We have a number of players coming back which should give us more strength in depth in the second half of the summer,’ said Locke.