The striker's fifth goal in a week, allied to Manchester City's surprise defeat at Swansea, took the Reds to the head of the table and now, with 10 games to go, the champions are reluctant to relinquish the perch.
"Fair enough, our form in Europe has been disappointing. But in the Premier League we've had very tough games and played a lot of the big teams. Sometimes we haven't been at our best but we've got the wins.
"It's great credit to the team for the hard work and spirit we've shown to keep tallying up those points. I think we fully deserve to be top."
United have shown admirable patience to overturn Manchester City's five-month stint at the head of the table, and similar patience was on show in Sunday's victory over Roy Hodgson's Baggies.
"They came here and made it difficult for us," conceded Rooney. "They got a lot of men behind the ball. So getting the goal in the first half helped settle us down and we could have scored a lot of goals today. But the most importatnt thing was the three points.
"Sometimes you need to keep your head and keep your patience. We managed to do that and create a few chances and thankfully I got the goal before half-time which settled us.