Lukaku finished off a neatly-worked United move to draw his side level with Chelsea and was instrumental in Jesse Lingard's winner.
Ex-Liverpool captain Jamie Carragher dubbed the game a "big result" for Man United but "an even bigger game for Lukaku."
Carragher went on to add that Lukaku managed to change the Scouser's opinion of him: "For the winning goal, I've always felt he's just a goalscorer, there isn't too much more to his play, he's not great at hold-up at times and he doesn't work the channels, but this just answers me and plenty of his critics - there is more to his game."
Souness declared himself a "fan" of the Belgian. "I'm a fan. Forty games now, 22 goals, it's the hardest place to play football and the hardest position on the pitch - that and the goalkeeper. It's about how many games you play and how many goals you score. He does a great job," Souness added.
According to Big Rom's manager, Jose Mourinho, the striker played "fantastically well." The Belgian will surely be content with his performance in a crucial game when he silenced the critics.