Wilfred Ndidi’s acrobatic goalline clearance was the first indication as to the long night ahead of the Foxes, as the Nigerian lunged towards his own goal to deny Rodrigo Bentancur, whose flicked header from a corner was on its way into the net.
Moments later Spurs’ £65m summer signing Dominic Solanke should have bagged a debut goal, but directed a tame header at Mads Hermansen from six yards out.
Eventually Ange Postecoglou’s men got their goal, and there were few surprises as to who created it.
Former Leicester man James Maddison had already dictated play for nearly 30 minutes when his in-swinging cross was flicked home by Pedro Porro.
Debate raged whether it was a deft header or fortunate deflection off the Spaniard’s shoulder, but few could deny that the North Londoners deserved their half-time lead.
At 37 years of age and without much of a pre-season, Vardy was a surprise starter and a peripheral figure in the first half, but Leicester’s only remaining figure from their fairytale Premier League title still had at least one more magical top-flight moment to give.
Within 15 minutes of the restart, the veteran forward snuck behind a sleeping Spurs defence to head home an equaliser from close range that arrived completely against the run of play.
It could have got even better for Vardy, as minutes later he was superbly denied by visiting goalkeeper Guglielmo Vicario after being played in by Facundo Buonanotte.
A clash of heads involving Betancur that saw the Uruguayan stretched from the field forced a lengthy stoppage, and resulted in nine minutes of time added on.
However, neither team was able to find a winner, with Ndidi going closest for the home side with a header that was turned away by Vicario.
While the hosts can take plenty from their unlikely comeback, it's a far-from-ideal start for Spurs, who've now won just two of their last eight league matches.
Flashscore Man of the Match: James Maddison (Tottenham Hotspur)