Leicester returned to form in style, racing into a 4-0 lead as Vardy ended a run of 16 club games without a goal.
Jamie Vardy ended his Leicester City goal drought with a brilliant hat-trick as the Premier League champions crushed Pep Guardiola's shambolic Manchester City 4-2 on Saturday.
Leicester returned to form in style, racing into a 4-0 lead as Vardy ended a run of 16 club games without a goal by scoring a fine treble.
Andy King also scored for the champions as Guardiola's men were torn apart, suffering an embarrassing reverse despite late goals by Aleksandar Kolarov and Nolito halving Leicester's winning margin.
After a bruising 3-1 defeat by Chelsea last weekend, Guardiola faces more tough questions, while Leicester manager Claudio Ranieri can finally enjoy a much-needed win after a poor defence so far of their title.
A dream start for Leicester came in only the third minute as Vardy's barren spell ended with the finishing touch to a pleasing move.
Riyad Mahrez started it with a fine touch to bring down a high ball and lay it off to Islam Slimani, who slid a pass to the feet of Vardy.
The England striker slotted a shot into the bottom-left corner with the composure of a man who had been scoring prolifically.
The lead was doubled within three minutes courtesy of another goal from the top drawer as Robert Huth headed down a Christian Fuchs throw and Slimani laid off a pass to King.
But it was still no more than a half-chance until the Wales midfielder unleashed a fantastic curling shot that flew in off the fingertips of goalkeeper Claudio Bravo.
On 12 minutes it might have been 3-0 when another Huth knock-down found Slimani, but the Algerian striker sent a shot over.
Visitors City produced a rare moment of promise on 15 minutes when Kevin De Bruyne tried his luck from just inside the Leicester penalty area with a shot that flew just wide.
But five minutes later the damage got worse for the visitors as Leicester turned on the style for their third goal.
A long pass from Fuchs was cushioned brilliantly by Mahrez into the path of Vardy, who rounded Bravo and rolled a low shot into the gaping goal.
It could have been 4-0 moments later when Mahrez danced his way to the edge of the area with some fine footwork, but saw his shot turned away to safety by Bravo.
The visitors were denied a penalty in first-half stoppage time when Kelechi Iheanacho went down under Marc Albrighton's heavy challenge.
Seconds later Albrighton presented a chance for 4-0 on a plate for Slimani, only for the striker to head an excellent cross wide.
The visitors increased their tempo after half-time and began to pin Leicester back inside their own half.
Pablo Zabaleta and De Bruyne both had shots blocked in a goalmouth scramble before Ilkay Gundogan went close to giving his side a lifeline, shooting narrowly wide from Iheanacho's lay-off.
But Slimani had another chance when he glided into the penalty area, only to see his shot saved low down by Bravo.
Vardy made it 4-0 on 78 minutes as he completed his hat-trick, pouncing on a terrible back-pass from John Stones and scoring with a shot that just crept over the line from an almost impossible angle.
City made the scoreline look a little more respectable in the closing stages with two impressive goals of their own.
First, Kolarov curled a fine free-kick into the top corner from 20 yards with City's first shot on target and then Nolito side-footed home superbly from a Kolarov cross.
But Leicester held on to claim a vital three points and condemn their visitors to a crushing defeat.