The Argentine forward was repeatedly reminded by the home fans as to how his departure from Old Trafford after only a season of gametime was viewed as the worst possible form of treason.
The France worldwide scored the Ligue 1 giants' second goal after Presnel Kimpembe's opener and Mbappe felt that Thomas Tuchel's men did their talking on the Old Trafford pitch.
Young crashed into Di Maria as he chased a wayward pass, clattering him off the pitch but escaping with a talking-to from the referee.
"The second goal was quality by them".
It would have been more but for some fine goalkeeping from David de Gea. "It's a magical evening, it's flawless", he said. "It was a nice comeback for him". "It was a level up for us tonight". "I am happy with what I did with [Manchester United midfielder Paul] Pogba, but I am still focused on our collective win". "He's always super reliable".
Without two of its usual front three, the French league leader commanded the midfield instead, with Marco Verratti the orchestrator. "We needed time to adapt".
Solskjaer lost both Anthony Martial and Jesse Lingard to injury in the first half as United crumbled to the heaviest home European loss in the history of the club.
In addition to matching the two legends of the game, Mbappe is now also outscoring players such as Harry Kane (13 goals), Radamel Falcao, Alexis Sanchez and Roberto Firmino (all 12 goals), as well as Paulo Dybala (11 goals) in the competition, while Chelsea superstar Eden Hazard sits on just eight strikes.
Solskjaer was in no mood to pull his punches with the Chilean, saying: "I can't do anything about Alexis Sanchez".
"We have character, because it's not easy to play here, Man United are one of the best teams in the world". This will pile added pressure on Ole Gunnar Solskjaer's men who will now have to travel to France knowing that if they concede there it will be well and truly game over. "Our players today, disappointed, of course, but I also think they know we need to step up our level to get to the level we want to get to", said Solskjaer.
It was Solskjaer's 12th game since he took over as interim manager from Jose Mourinho and his side were out-performed by superior opposition.
None of the previous 34 teams to lose the first leg of a Champions League knockout match at home by two or more goals have progressed to the next round.
"The support was wonderful", the Germany global said. It was one of those experiences that can go either way, but it's not going to be a season-defining one for us.
Aside from victories in north London against Arsenal and Tottenham, facing PSG was United's biggest test since beating Italian champion Juventus at Turin in November in the group stage.
For around 20 minutes, the Champions League glory days really did feel like they were back for Manchester United. Further, the suspension of Paul Pogba for the away leg of the Champions League encounter will be a hard nut to crack given how reliant the Norwegian is on the Frenchman.
He will need that sort of attitude from his players at the Parc des Princes on Wednesday 6 March - with the return leg exclusively live on BT Sport - particularly considering they'll have to do it without the driving force of their recent revival, Pogba.