Winger James Wise led the way with a hat-trick of tries on Saturday.
Senior coach Will Knight was pleased to see his side exact full revenge for the defeat they suffered at Cobham earlier in the season.
He said: ‘For me it was a good marker to show how far we have come.
‘Cobham had no answer to us when we started to play the rugby we know that we are capable of.
Portsmouth transfer news: Blues receive bids for former Luton and Millwall midfielder
'Is proving one hell of a signing.... A real livewire' - Portsmouth match ratings from 2-0 win at Cheltenham
Transfer gossip: Portsmouth eye raids for ex-Chelsea man and Charlton Athletic's former Wigan Athletic midfielder
Portsmouth boss Danny Cowley hails squad depth as tactical masterclass at Cheltenham pays off
14 splendid photos from Portsmouth’s 2-0 win against Cheltenham in sun-soaked League One encounter
‘In the end we just turned on the power and blew them away to score six tries in the second period.
‘All this points well towards the future.
‘The most pleasing aspect was seeing the players taking responsibility for decisions.
‘It was good to have captain Joel Knight back in the centre, our wingers finished well and the forwards provided the platform.
‘A lot of the pieces of the jigsaw are starting to come together.’
The home side trailed 22-17 at the half-way stage after an evenly fought opening half.
The visitors scored first before Knight put his side on the scoreboard with a penalty.
Tries from Luke Warrington and Wayne Dugan gave the impetus back to the hosts.
However Cobham snatched two more tries and a penalty to get their noses back in front.
It was a totally different story in the second half as Havant took control.
Almost straight from the restart Joel Knight showed great strength to go over for a try.
Within two minutes Wise went over for the first of his hat-trick.
Other tries from Scott Morris and Will Owen completed the rout.
Will Knight added: ‘There are plenty of positives to take forward.
‘We have a break now before a big game at title challenging Sevenoaks.’
In London three south west United Services Portsmouth went down to a third successive defeat losing 26-10 against Andover at Burnaby Road.
Petersfield lost a high-scoring affair 49-31 at Old Whitgiftian.