A lively start saw James Morrison's ninth-minute effort from range denied by a brilliant Alex McCarthy save, diving wide to his right, minutes before Garath McCleary's overhead attempt forced Baggies keeper Ben Foster to get his hands to the ball down the other end.
West Brom defender Jonas Olsson put his late first-half header against the woodwork from a corner and then it was Morrison again denied by McCarthy with a stinging 56th minute volley which the Royals gloveman did well to keep out.
The sole goal of the contest came with just under 20 minutes left, when Romelu Lukaku in his first Albion start, controlled the ball just inside the area before deploying a low shot past McCarthy for his second goal since his loan move from Chelsea.
Reading were close to a leveller when McCleary found Hal Robson-Kanu at the back post but he was unable to test Foster as Steve Clarke's great start to life as West Brom manager continued with a third victory.
The lot of points put Albion third on the table, with some clubs behind them still to play tomorrow, as Brian McDermott's Reading dropped to the bottom of the table with a third straight defeat.
The Hawthorns, West Bromwich - 23,854
Yellow cards:WBA - Claudio Yacob 89' REA - nil