The forward, who is joint top of the league's scoring charts this season with Chelsea's Cole Palmer missed FA Cup semi-final win over the Blues
The win lifts reigning champions Leicester, who have spent much of the season facing the threat of relegation, up four places to the relative safety of 11th, nine points ahead of third-from-bottom side Swansea City, with four games to play.
Second-half substitute James McClean provided a much-needed injection of pace and trickery on the left for West Brom, but despite plenty of possession they could not find the back of the net, yet they remain eighth despite losing their last four league games and failing to score in five.