Ole Gunnar Solskjaer’s side kick-started their European campaign with a brilliant 2-1 win over French champions PSG in Paris on Tuesday night.
Bruno Fernandes – captaining United in the absence of Harry Maguire – scored a first-half penalty, but you feared for the Premier League club once PSG equalised in the second half.
However, Marcus Rashford rifled home a superb strike late on to give Manchester United another huge win over PSG, who they also beat in the Champions League 18 months ago.
Red Devils goalkeeper De Gea said: ‘It’s massive.
‘You play away the first game against PSG and you know they’re a difficult, top team. To get the three points today for us is massive.
‘It gives us confidence to keep going and now we have another big game on Saturday. We need to keep going and winning games.’
De Gea added: ‘We had good memories of this stadium from the last time we played here.
‘It was amazing but today we showed again we are Manchester United. We can beat big teams like PSG, playing well and creating good chances.
‘I’m really proud and really happy for all the players, for the team and for the club, for everyone. That’s why we are Manchester United.’
Manchester United midfielder Paul Pogba has also reacted to the impressive victory over PSG, posting on Instagram: ‘Great game, great win! The Champions League is back!’
Solskjaer’s side return to Premier League action on Saturday, with Frank Lampard’s Chelsea travelling to Old Trafford.