Steve Lovell felt Gillingham took the game to Pompey as they upset the league leaders.
The Gills boss believes his team were rewarded for not sitting back as they picked up a surprise win at Fratton Park.
Lovell’s team ended the 11-game unbeaten league run of Kenny Jackett’s men with a 2-0 success.
That’s despite struggling in the league and not winning in 10 games - a run stretching back to August 11.
Tom Eaves’ spectacular striker and Alex Lacey’s first-half stoppage time effort made the difference as Pompey defended poorly from a corner.
Lovell told www.gillinghamfootballclub.com: ‘We showed we’ve got what it takes to win games in this league.
‘Nobody gave us a chance coming down here today apart from us as a group, everybody gave everything and we’ve got something out of it.
‘I like to go and take the game to the opposition and it was no different.
‘We’ve got players in the side that can go and hurt teams and that’s what they did, we defended well as a group and I thought we thoroughly deserved it.
‘I’m very proud of all the boys.
‘We are not a team that likes to sit back and go for a 0-0; I like to take the game to the opposition and I know Kenny and Portsmouth have been on a great run, but we had a go at them and it worked, I’m delighted.’
Lovell was delighted to reward the 550 travelling Gillingham fans, who have endured a bleak period.
And he was pleased they saw a couple of goals the manager felt were of impressive quality.
He added: ‘They were brilliant – Tom knew exactly what he was going to do, and he finished it off magnificently.
‘Lacey’s was the same and it was a great finish. It came at a great time for us, just before half-time.
‘They (Gillingham supporters) have come down here and supported us when nobody gave us a chance coming down here.
‘I’m happy for everybody that travelled down, and everybody connected with the football club.’