John Sheridan praised 10-man Notts County for "battling their socks off" as they recorded their best result of the season at Portsmouth.
In an open first half, the Magpies could have
taken the lead early on when Rob Milsom's shot hit the crossbar.
Adam Campbell did make the breakthrough with a terrific lob before Conor Chaplin equalised.
But the striker scored the winner with a terrific finish from Jonathan Forte's pass, before Aaron Collins saw red for a tackle on David Forde which the club will appeal.
Sheridan said he was thrilled with the win which took Notts up to sixth in the table and was their fifth on the road this term.
The Magpies celebrate Adam Campbell's winning goal.
"The most pleasing thing was the way we battled," he said.
"We've played, in my mind, the best team in the division.
"I knew it would be a very hard game but to come away with three points, after the disappointment of the last two or three games, was excellent.
"We've battled our socks off. Adam Collin had a stormer, but my tactics were wrong in the first half.
"I played Richard Duffy in front of the back-four and there was too much pressure. Once I made the change we were a lot more comfortable.
"We showed them too much respect, but I told the players to believe they could get something out of the game.
"It's full credit to them and I am just pleased for the supporters because it's a long way to travel."
Read more: Portsmouth 1 Notts County 2: Match report
Notts will appeal against Aaron Collins' red card.
Pompey were booed off at full time, but could have snatched a point through Carl Baker who was denied by Adam Collin who made several stunning saves.
He said Notts deserved credit for the way they stopped them from playing in the second half.
"I thought we were excellent in the first half," he said.
"We created a lot of chances and looked a threat.
"These goals we are conceding are disappointing, though, when we are not under any pressure.
"From there the second half became a bit of a joke. It never got going.
"You have to give Notts County credit because we never got any fluidity going.
"When games go that way we usually come off second best."