Tottenham were left ruing a host of missed chances as Leicester held out to move into the top half of the table with victory at the King Power.
A deft lob from Jamie Vardy and a curling shot from Riyad Mahrez gave the Foxes a healthy half-time lead.
Christian Eriksen contrived to volley wide from six yards out before Harry Kane rifled in with 12 minutes to go.
Fernando Llorente then stabbed over the top from close range as the visitors hunted an equaliser in vain.
The hosts rode their luck to the end – with referee Anthony Taylor waving away a strong injury-time penalty claim as Danny Rose went down under Wilfred Ndidi’s challenge – but emerged with all three points from only 37% possession
Claude Puel was sacked by Southampton at the end of last season
The victory is the biggest result since Claude Puel took charge and the Frenchman has amassed a quietly impressive record in his first month on the job.
The Foxes’ only defeat in his five league matches came to runaway leaders Manchester City and they have edged up from 14th up to ninth over that time.