The England U21 ace came off the bench to clinch the three points.
Speaking about his first-ever top flight goal, Berahino said: "I can't believe it and it just shows how God is really great.
"The gaffer has given me the chance and believed in me so I thank him and the club for being so good to me.
"I just don't want the journey to end now. I want to carry on and build on it for many years to come.
"Scoring against Man United is everyone's dream, youngster or a professional older player. God is great so I thank God."
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