After an hour of deadlock at the King Power Stadium, Vardy took matters into his own hands, latching on to a long ball pumped down the right, looking up and launching an unstoppable 25-metre rocket over stranded goalkeeper Simon Mignolet.
The England striker then showed his poacher’s instinct in scoring his side’s second, his 18th league goal of the season, to keep Leicester three points clear of Manchester City, who made a meal of beating relegation-threatened Sunderland 1-0.
Sergio Aguero scored his 12th goal in his last 10 league matches to earn City the points a day after it was confirmed manager Manuel Pellegrini would be replaced by former Barcelona coach Pep Guardiola at the end of the season.
With 14 games of an enthralling season left, Leicester have 50 points with City on 47 ahead of their top-of-the-table blockbuster at the Etihad Stadium on Saturday.
North London rivals Tottenham Hotspur and Arsenal have 45.
Tottenham striker Harry Kane also struck twice, after Dele Alli’s early opener, as Spurs crushed Norwich City 3-0 away to leapfrog Arsenal into third spot, fuelling the club’s belief that a first title since 1961 is within reach.
Arsenal are stalling after a 0-0 home draw with Southampton left them without a league win in four games and without a goal in their last three, the first time since 2009.
Life is looking a little brighter for Manchester United manager Louis van Gaal after his side finally rediscovered a spark at Old Trafford.
They had not scored in the first half of their last 11 home matches, piling pressure on the Dutchman, but they turned on the style against Stoke City with Jesse Lingard and Anthony Martial on target before halftime and Wayne Rooney completing a 3-0 win after the break with his 99th home league goal.
United remain in fifth place with 40 points.
As so often this season though, Vardy stole the limelight and left his manager Claudio Ranieri purring.
“Amazing. The first goal was unbelievable,” the Italian said.
While Ranieri heaped praise on his players, Liverpool manager Juergen Klopp was left fuming after his side slipped 16 points behind them in eighth place.
“I’m not too fine with our game today,” a downbeat Klopp said. “Today would have been a good day to show we are ready for this. I need a few more seconds to calm down.”
Man City were under the cosh for long periods at Sunderland but hung on for Pellegrini’s 65th win in 100 Premier League matches in charge — a record bettered only by former Chelsea manager Jose Mourinho (73).
Pellegrini, still fighting for silverware on four fronts despite his imminent exit, praised his side’s resolve.
“It is not our style to play with nine defenders but it was our third game in a week and it was impossible to have a high pace with all our injuries,” he said.
Tottenham’s teenage midfielder Alli needed only two minutes to put his side ahead at Carrow Road, although he went off early in the second half feeling unwell.
Not that it took the shine off another clinical Spurs display as they won a fifth game in a row in all competitions.
Bottom club Aston Villa’s hopes of avoiding relegation suffered another setback when they had Jordan Ayew sent off after 17 minutes for elbowing Aaron Cresswell before slipping to a predictable 2-0 defeat at sixth-placed West Ham United.
Bournemouth gained three vital points with a 2-1 victory at Crystal Palace, moving them seven points above the bottom three, while Swansea City are five points clear of the drop zone after drawing 1-1 at West Bromwich Albion.