Portsmouth piled on the misery for struggling Norwich as they made it back-to-back Championships victories with a 1-0 triumph at Carrow Road.
Pompey followed up their midweek win against Sheffield United with a hard-fought success in East Anglia, with a 51st-minute penalty from striker Marezi settling the issue.
It was a fifth successive league defeat for the hosts and there were calls for sporting director Ben Knapper to go from frustrated supporters at the final whistle.
Before the match there was a minute's applause to honour Norwich's former joint majority shareholder Michael Wynn-Jones, who died earlier this month - but the emotional tribute failed to inspire the hosts in what was a dull first half.
Neither side managed an effort of any description in the opening 35 minutes, with Pompey wide-man Ryan Kavuma-McQueen finally breaking the tedium by sending a shot well over from distance.
A couple of minutes later Adrian Segecic saw a shot well blocked after good work on the right from Abu Kamara, while at the other end weak long-range shots from Ruairi McConville and Anis Ben Slimane were all Norwich had to show for their efforts.
The deadlock was finally broken in the 51st minute, with Pompey going ahead from the spot.
Jacob Wright was penalised for clipping Kamara in the box and Serbian striker Marezi stepped up to convert the penalty for his third goal of the season.
Norwich responded in spirited fashion, with Ben Slimane testing Nicolas Schmid with a low drive and Jovon Makama volleying over after being picked out by substitute Lucien Mahovo.
The Canaries kept pressing and were desperately unlucky on 77 minutes when Pelle Mattsson's shot from the edge of the box came back off the upright, with Schmid well beaten.
It was a brave effort from Norwich, but not enough to prevent them from slipping to an eighth defeat in 11 league games.
Norwich's Philippe Clement:
"I am very disappointed, very frustrated. I saw a lot of passion out there, a lot of effort, but not enough overview.
"We had some good possession but at important moments we would make the wrong pass, or try a shot from 30 yards. It's about getting the balance right between their hearts and their brains.
"I understand the frustration of our fans with our results (eight defeats in 11 league games) and all I can say is that I will work even harder than I did last season to turn it around.
"We have the quality in the squad to do that and we need to go out on the pitch and change things. You can't change anything with words."
Portsmouth's John Mousinho:
"I know the fans felt devastated after the derby defeat, and it was the same with the players and staff.
"I didn't want the players to forget the pain after that. I wanted them to feel it when they came back into training, use it in a positive way, to come back in midweek and get a result.
"They did that against Sheffield United and now they have come here and done it again. All credit to the players, they have done it themselves and I thought we deserved to win.
"We were excellent in the first half, playing a lot of good football up to the Norwich area, although I can't remember us testing their keeper.
"It was the same at the start of the second half, and our energy and counter-press got its reward when we won the penalty. After that all the squad did a good job to see the game out.
"I was really pleased with the way everyone went about their business and believe there is even more to come from this group of players, especially when we have a few more back from injury."
