The Spaniard was suddenly thrown into the spotlight in the final minute of the game when the home side were awarded a controversial late penalty and, thus, a chance to equalise.
United had only just taken the lead with Jesse Lingard's emphatic 89th-minute strike and hearts were in mouths, heads in hands when referee Martin Atkinson pointed to the spot following a handball from Luke Shaw after consulting the TV monitor.
In a stadium fully consumed by the late drama, De Gea remained cool to save Mark Noble's penalty.
"It was a bit crazy at the end, a great goal of Jesse, a stupid penalty, lucky penalty for them at the end of the game," De Gea told MUTV.