The game looked like it was going to ebb out with a 0-0 draw, but Antonio Valencia opened the scoring late on and then Young turned tightly and somehow managed to bend the ball between goalkeeper Robinson and the post.
The win means United are five points clear of nearest rivals Manchester City with just seven games of the season to go, something which made substitute Young very happy.
He told Sky Sports: "I think it was a massive game for us. We knew if we won today we would go five points clear at the top. It's a great result and a great performance.
"It's a crucial time in the season, everyone knows that. It's a squad game. The manager made a few changes tonight but everybody's in the squad to do a job and we got that done tonight.
"I think patience was important. If you look at how many balls Antonio (Valencia) put in the box, we were always going to create chances and when that first goal goes in it's a great feeling."
"It's a massive lead (at the top of the table) for us," he continued.
"It was a massive game tonight and to get that goal, that we knew was going to come at some point - whether he says it was a shot or a cross! It went in the back of the net so we're just delighted with that.”