Following a moving pre-game tribute to the late Craig Shakespeare, Tottenham - spearheaded by their new £65m man Dominic Solanke - immediately asserted their dominance at the King Power, where Vardy started up front for the hosts despite being ruled out through injury in midweek.
The Foxes veteran saw little of Guglielmo Vicario's goal in the opening 45, though, as Tottenham gave Steve Cooper's side a harsh welcome back to life in the Premier League and deservedly went ahead on the stroke of the half-hour mark through Pedro Porro's glancing header/shoulder.
With new Leicester man Oliver Skipp - just arrived from Tottenham - watching on from the bench and another ex-Spurs man in Harry Winks being overrun, James Maddison, also reuniting with his old team, provided the deft delivery for Porro to meet, as the Spaniard bagged the goal that the visitors' dominance warranted.
Ange Postecoglou's side were otherwise found wanting in front of goal, though - wasting a number of chances to extend their advantage - and such profligacy proved costly when Tottenham's age-old enemy Vardy took advantage of some horrendous marking to head home the equaliser.
The 37-year-old's 103rd Premier League goal since turning 30 triggered an unforeseen Leicester revival, albeit one that was stopped in its tracks when Rodrigo Bentancur - who ruptured his ACL at the King Power in 2023 - was knocked unconscious and subsequently left the field on a stretcher.
The lengthy stoppage did indeed halt the Foxes' momentum, but Spurs never looked like regaining the lead in the dying embers - despite seeing over 70% of the ball - in a performance that left Postecoglou with more questions than answers.
Tottenham should have been out of sight by half time, and Leicester had no right to claw their way back into the contest based on their performance in the first 45, but the vigour Cooper's men that displayed in the second half should lead to cautious optimism for the weeks ahead.
LEICESTER VS. TOTTENHAM HIGHLIGHTS
Pedro Porro goal vs. Leicester (29th min, Leicester 0-1 Tottenham)
Tottenham have lift-off for the new season, thanks in no small part to an old Leicester flame.
The Lilywhites work it down the left again before Son Heung-min lays off Maddison, who has time to deliver a crisp inswinging cross into the box, which is met by the charging Porro.
The right-back does not get the cleanest connection on the ball, which appears to come off his shoulder, but he delicately glances the ball past Mads Hermansen's futile reach and into the side of the net.
Jamie Vardy goal vs. Tottenham (57th min, Leicester 1-1 Tottenham)
Leicester have barely had a sniff in the Tottenham half, but they unexpectedly find themselves level early in the second half through the perpetual Big Six tormentor himself.
A Victor Kristiansen cross from the left flashes across the face of goal and misses everyone, but Abdul Fatawu keeps the chance alive on the opposite side of the penalty area and sends the ball back into the mixer.
It goes over Bobby Decordova-Reid's head, but Vardy is totally unmarked, stays onside and cannot miss with a bottom corner-bound header from a few yards out. Atrocious defending from Tottenham.
MAN OF THE MATCH - MADS HERMANSEN
There was little that Leicester number one Hermansen could have done to deny Porro and Tottenham in the first half, but when the Lilywhites continued to surge forward, the Dane stood tall and kept the visitors at arm's length.
Helped by Spurs' lack of ruthlessness, Hermansen made five saves and was quick coming off his line to snuff out any danger before it developed, and a point was more than warranted. Special mentions for Fatawu and Porro too.
LEICESTER VS. TOTTENHAM MATCH STATS
Possession: Leicester 29%-71% Tottenham
Shots: Leicester 7-15 Tottenham
Shots on target: Leicester 3-7 Tottenham
Corners: Leicester 2-13 Tottenham
Fouls: Leicester 11-12 Tottenham
BEST STATS
WHAT NEXT?
Leicester hit the road for their first Premier League away game of the season on Saturday, facing another London outfit in Fulham, where ex-Spurs man Skipp could make his debut after joining too late to be considered for tonight's fixture.
Meanwhile, Tottenham's maiden home match of 2024-25 comes against Everton on Saturday afternoon, but immediate concern turns to the conditions of both Porro and Bentancur following their enforced withdrawals at the King Power.