The winger put the Foxes ahead in just the ninth minute when he lashed a powerful volley into the corner of the net in his first run-out since joining from Le Havre earlier this month.
Striker Chris Wood also featured against his former club for the young Foxes, who were pegged back by Wesley Atkinson on the stroke of half time only for Michael Cain’s majestic free kick to seal the victory at Albion’s training ground.
Development Squad boss Steve Beaglehole told LCFC.com: "It was a very good game, a very competitive game and a few people said it was one of the best games they’ve seen at Under-21s level.
"They (West Brom) are a good side and have played some good football but we stuck at it and made it a proper game. There were plenty of good tackles and challenges. We started off brightly, much more like ourselves after the Bolton defeat and we had a good tempo.
"George Taft came back for his first start since his knee injury and it was the best game he’s had for us, I thought he was outstanding.
"He made some great blocks and headers and overall it was a good, workmanlike and competitive performance.
"The most sickening thing for me was the way we lost to Bolton [last week], because they’re nowhere near as good as West Brom, and if we’d have won that we’d have been right up there [in the league], but it’s very tight.
"We’ve got some difficult games coming up, but the squad is getting stronger."
WEST BROM SQUAD (from): Atkinson, Birch, L. Daniels, D. Daniels, Francis, Gayle, Howkins, A. Jones, C. Jones, Nabi, O’Sullivan, Rose, Thorne, Ward, Wright
GOAL: Atkinson 45
CITY: Logan (c), Pearson, Elder, Taft, Sesay, McCourt (Dawson 57), Cain, Panayiotou, Mahrez (Paratore 77), Wood (Blyth 86), Dodoo
SUBS NOT USED: Kennedy, Sharpe
GOALS: Mahrez 9, Cain 80