Tensions flared during the crucial game at the Etihad with the stakes so high, and the Ligue 1 side imploded in the second half with Angel Di Maria shown a red card for a stamp on Fernandinho, with PSG stars involved in a few stand-offs with the official.
City won 4-1 on aggregate after Mahrez scored a brace to earn a 2-0 victory on the night and sent his side through to their first ever Champions League final.
PSG star Marco Verratti claims referee Bjorn Kuipers told him 'f*** you' during their loss to City
Leandro Paredes (second left) also alleged he was insulted in a similar manner by the official
After the game Mahrez accused PSG of 'losing their nerve' after the red card and slammed their players for 'kicking us', but the French outfit incredibly claimed they were victims of a verbal attack from the man in charge of the contest.
Ander Herrera told RMC that his team-mate Paredes had been told to 'f*** off' by Kuipers, and complained that the players would have been hit with a lengthy ban had they said something similar to him.
'We talk about respect with referees,' he said. 'The referee tonight said "f*** off" to Leandro Paredes. It's incredible. If we say that we get a three-four match ban.'
Tensions flared during the Champions League semi as Angel Di Maria (far right) was sent off
Verratti backed up the claims and insisted he too had been insulted by the official, saying: 'He said "f*** you" to me... I talk to referees a lot but I never say that or I get a 10-game ban.'
PSG were second best for much of the contest having come into the game losing 2-1 after a home defeat in the first leg, but they failed to pull themselves back into the contest.
The Parisiens didn't even manage a shot on target as they were unable to put a glove on Pep Guardiola's men, who were dominant throughout and shackled the likes of Di Maria and Neymar and defended as a unit.
Ander Herrera said Kuipers' words were 'incredible' and said PSG players would have received a lengthy ban if they had said similar comments to him
Pundit Rio Ferdinand said the defeat was 'embarrassing' for the Ligue 1 outfit and that City 'took the mick' with how easy it was to brush them aside in such a huge game in the Champions League.
'By the end of it they were taking the mick,' he told BT Sport. 'It was embarrassing for PSG, a team who are full of experience and full of winners. Huge hats off to Pep [Guardiola] and his team.'
For City, it was simply a night to remember, and while PSG's top stars failed to sparkle on the big stage, there were top performances from Mahrez and young English star Phil Foden.
City were dominant on the night, with top displays from Phil Foden and Riyad Mahrez (centre)
Ferdinand hailed the midfielder as the best young player in world football and said he had to be a shoo-in to start for England at Euro 2020.
'At the moment I would say Phil Foden is the best young player in the world right now on form. [Erling] Haaland is yet to play at this level. In terms of this moment, Foden is the best on form,' the former Man United defender said.
'Its the semi finals of the Champions League, an important game - they've never been further than this. He's come into this team and he has created match defining moments.
'I can't wait, I'm salivating - you fast forward to the Euros... he has to be one of the first players on the team sheet because he's doing it on this level.'