Kieran Trippier's corner was played short to Eriksen, who floated in an inviting cross for Davison Sanchez to power home a diving head for his first Tottenham goal in the 33rd minute.
Son claimed he was tripped by Harry Maguire in the first half, but Oliver showed the South Korean a yellow card for simulation, before later awarding a penalty to Leicester when he adjudged that Jan Vertonghen had fouled James Maddison.
And it could not have gone worse for Vardy, who saw his penalty saved before Spurs extended their lead thanks to Christian Eriksen just minutes later.
Son appeared to be tripped by Leicester defender Harry Maguire in the first half but Oliver brandished a yellow card to the South Korea global with replays showing Maguire's boot had made contact with his shin.
On all three occasions, Maximilian Philipp deputised for the injured Reus and he can be expected to line up against Spurs if the Germany global does not make it.
Llorente pounced on Ricardo Pereira's poor clearance and teed up Eriksen for a superb strike from the edge of the area for his first goal since January 1. But they did get one back on 73 minutes, Tielemans finding Pereira down the right and his low cross was poked in from close range by Vardy.
What does it mean? He was key, but when you need this type of performance from your top player, they were there.
"I said to Jamie Vardy he can take the penalty".
What happens against Tottenham Hotspur tomorrow will go a long way in determining what the actual outcome will be vis-à-vis Leicester's season and Puel's future.
- Tottenham against Leicester has now joined the Sheffield derby as the most played top-flight fixture without ever recording a goalless draw (84 meetings).
Pochettino's side beat Leicester 3-1 at Wembley in a Premier League match moved to Sunday to satisfy the demands of the sport's television paymasters.
- Spurs have received four bookings for simulation in the Premier League this season, the joint-most in the competition alongside North London rivals Arsenal.