Leicester were handed a second consecutive defeat as Watford recorded a 2-1 victory at Vicarage Road.
The Foxes slipped out of the promotion spots after their fourth defeat of the campaign, as Gianfranco Zola's side completed a deserved win.
On-loan midfielder Almen Abdi gave the home side a 14th-minute lead as he clinically netted his fourth goal of the season.
Fernando Forestieri made it two after reacting the quickest following Kasper Schmeichel's terrific save to deny Daniel Pudil.
Leicester pulled one back three minutes later as top scorer David Nugent scored his sixth of the season.
But Zak Whitbread was dismissed for two bookable offences in the 83rd minute to kill off hopes of a comeback.
Watford welcomed back suspended duo Pudil and Nathaniel Chalobah to the side, while Abdi returned from injury.
Leicester were without the suspended Ritchie De Laet and the injured Jamie Vardy, while Lloyd Dyer dropped to the bench as Matty James started in a three-man midfield.
Watford started the brighter side and had the first sight of goal after 11 minutes but Troy Deeney blazed his effort from the edge of the area high over the bar.
But the Hornets opened the scoring three minutes later. A clever pass from Forestieri released Abdi on the right and the midfielder advanced towards Schmeichel before slotting a low effort into the bottom corner.
Schmeichel was called into action again in the 20th minute as Wes Morgan's clearance fell to Forestieri whose low effort was well held by the Leicester goalkeeper.
It took the Foxes until the 30th minute to create an opening, with Ben Marshall forcing a save out of Manuel Almunia, before a powerful Morgan header was cleared off the line by a well placed Jonathan Hogg.
Nigel Pearson replaced Danny Drinkwater with Dyer at half-time, as he looked for more width from his side, but the change did not have an immediate impact as the second half got off to a quiet start.
And it was Watford who eventually had the first opening as Deeney forced a stop out of Schmeichel with a header just before the hour mark.
Pearson responded by bringing on Martyn Waghorn and Marko Futacs, but his side were soon two goals down.
Schmeichel pulled off a terrific save to prevent Pudil's effort, but Forestieri pounced on the rebound and tucked away the loose ball.
The visitors responded three minutes later as Nugent controlled Paul Konchesky's cross and fired a low effort into the corner of the net.
But any hopes of a comeback were scuppered as Whitbread brought down substitute Matej Vydra and was shown his second yellow card of the game.