Jamie Vardy scored twice as Leicester beat Watford in a hugely entertaining match to ruin Claudio Ranieri's return to the King Power Stadium.
Ranieri was in the opponents' dugout for the first time since guiding the Foxes to the 2015-16 Premier League title and received a great reception from the home fans.
But in a chaotic and thrilling game played in blizzard conditions, his current side played a big part in their own downfall.
There looked to be no danger when Jonny Evans launched a free-kick forward, but William Ekong ducked under the ball and that allowed James Maddison to fire the 16th-minute opener past Daniel Bachmann.