Riyad Mahrez marked his 100th Premier League match with a goal as Leicester City moved away from Watford in the mid-table battle.
Wilfred Ndidi fired the Foxes into a first-half lead and Mahrez – the first Algerian to make a century of PL appearances – doubled the advantage just before the hour-mark, breaking free down the right and slotting between Heurelho Gomes's legs.
Mahrez has now scored in Leicester’s last three matches against Watford – and Marc Albrighton added further gloss to the scoreline in stoppage time.
Leicester have leapt three places up the table into ninth place, while Watford have dropped to 15th.
Meanwhile, Craig Shakespeare has become only the fourth manager to win his first five PL home matches.