Marc Albrighton's superb goal set Leicester on their way to victory over Rennes in the first leg of their last-16 Europa Conference League tie.
The 32-year-old winger powered an effort into the top right corner after some excellent work by Harvey Barnes.
Until then, the hosts had struggled to contain a lively Rennes side that sit fourth in Ligue 1.
The Foxes' night got even better when Kelechi Iheanacho curled in a late second against the run of play.
The celebrations around the King Power suggested many felt Nigerian forward Iheanacho's late contribution may prove pivotal to the outcome of the tie, which resumes when the Foxes travel to France for the return leg on Thursday, 17 March (17:45 GMT).