There was another special moment for the Spaniard late in the contest, when he was replaced by Tomasso Martinelli three minutes from full-time, and given a standing ovation by supporters in all corners of the stadium.
"A magical moment for me and my family to come back to Old Trafford - my home," De Gea wrote on X, on Saturday afternoon.
"From the bottom of my heart - I want to say thank you for the reception - for all the love you shown me today."