After Robin van Persie had given the Reds the lead from the penalty spot when Patrice Evra had been fouled in the area by Marouane Chamakh, Rooney hit a beautiful shot into the top corner to seal a solid win.
"Today was a big result for us," Rooney said after the game. "We haven't played in 10 days so it was an important game. It was a good victory, I thought we played well and moved the ball well. It was a good win.
"It had [been tough]. We moved the ball well and could have created more chances," he added on Sky Sports. "Overall, we had it under control and we knew that once we got a goal we could get another and see the game out. It's always important, it's tough to get that first goal, thankfully Robin stuck the penalty away. We managed to get a second and thankfully we got the three points."
Rooney netted his first goal since appearing on the scoresheet against Hull City on Boxing Day, it was an impressive strike, letting Evra's cross from the left move across him but guiding the ball into the top corner. The United no.10 insists his new contract extension had no bearing on his overall performance.
"I just tried to do well for the team and to help us win. Whether I've signed a new deal or not, I always try and give 110% on the pitch and that's what I did," he added. "For my goal, the ball was set up nicely. I knew that if I got decent contact on it, I had a chance. Thankfully it's gone in."