Slaven Bilic's side had watched on over the weekend as Swansea City, Leeds United and then Preston North End all usurped them in the standings, leaving them in fourth at kick-off.
However, the Baggies are once again sitting pretty at the summit after brushing aside a Stoke team who had caretaker boss Rory Delap in charge for the first time.
Matt Phillips put the visitors ahead when he converted Grady Diangana's cross in the eighth minute and they rarely looked in danger of letting their advantage slip against opponents bereft of confidence.
Diangana was also heavily involved in West Brom's second, as he was fouled by Cameron Carter-Vickers inside the penalty area. Substitute Hal Robson-Kanu converted from the spot just six minutes after replacing Charlie Austin.
Defeat means Stoke - which fired Nathan Jones last Friday - remains stuck at the bottom, six points from safety.