Second half goals from debutant Timothy Castagne and a penalty brace from Jamie Vardy secured all three points for Brendan Rodgers’ side, as the Baggies comeback party was firmly spoilt.
Neither side created much in a poor first half in the West Midlands, with half chances for Harvey Barnes and Vardy the closest to an opening goal.
Leicester looked to put their foot on the gas after the break, and Castagne deservedly nodded them in front on 56 minutes.
West Brom stayed in the game from there, with Kasper Schmeichel called into action to deny Callum Robinson.
But with the Baggies unable to make their spells of key pressure count, Leicester and Vardy handed them a lesson in Premier League reality.
Baggies centre back Kyle Bartley tangled with Barnes inside the box, and Vardy showed his trademark dead eye to power home from the spot.
With the points already lost, West Brom lost their discipline in the closing minutes, as Dara O’Shea clattered Barnes over for another penalty.
And it was rinse and repeat from Vardy once again as the former England international showed Mo Salah he will push him all the way for the Golden Boot.
FULL TIME AT THE HAWTHORNS IT’S WEST BROM 0 LEICESTER CITY 3