The Algeria international’s effort rounded up the victory after Jamie Vardy’s spot-kick had given Claude Puel’s men the lead.
The Foxes nicked their third away win in the top-flight this season which moved them to the seventh spot in the log.
Impressed by the display, the former Le Havre’s winger then took to the social media to echo his feeling.
“Great victory, great goals and clean sheet,” Mahrez posted on Instagram.
The winger who has now registered nine goals across all competitions this season will be looking forward to another fine display when Leicester travel to the ABAX Stadium to confront Peterborough United in an FA Cup tie on January 27.