De Gea pulled off a string of fine saves during the match before Young scored late on to win the match for United.
It was a vital three points for United who kept pace in the race to finish in the top four of the Premier League after Liverpool, Arsenal and Tottenham Hotspur all won.
Young said United were indebted to De Gea and that he was delighted to grab the winning goal.
“We heard of results, others winning around us so it was vitally important to get a win here. It was great work by Wazza (Wayne Rooney), the ball fell to my feet and I put it away.
“People are always going to question the biggest club in the world. We concentrate on ourselves, listen to the manager and coaching staff and don’t listen to anyone else.”
United were dominant for the overwhelming majority of the game but were once again flaky in front of goal and wasted a host of opportunities before Young finally broke the deadlock in the 90th minute.
Wayne Rooney, Marouane Fellaini and Young all missed excellent opportunities to score while Papiss Cisse spurned Newcastle’s best chance at the other end. Van Gaal has now extended United’s run to just two defeats in 22 games which is of course the most important thing for fans.