Vardy was dismissed on 28 minutes after launching himself into a challenge on Mame Biram Diouf with his studs showing.
Claudio Ranieri lost Jamie Vardy and his own composure, but saw 10-man Leicester City display the spirit of champions in a 2-2 draw at Stoke City on Saturday.
Daniel Amartey completed the comeback in the 88th minute as he rose between two defenders to head home a Christian Fuchs cross and earn Leicester a crucial point after they had played for 62 minutes without Vardy.
Referee Craig Pawson, widely criticised for his failure to send off Manchester United's Marcos Rojo at Crystal Palace in mid-week, dismissed Vardy for a similar two-footed challenge.
He also showed Leicester five yellow cards in the final seven minutes of the first half, leading to tempestuous scenes at the interval.
Vardy was dismissed, for the third time in his career, on 28 minutes after launching himself into a challenge on Mame Biram Diouf with his studs showing.
It was a contentious decision and led to a Leicester meltdown, plus two goals for the home team.
Danny Simpson was booked after conceding a penalty for handball, from which Bojan Krkic gave Stoke a 39th-minute lead.
Four Leicester players followed Simpson into the book in the final seven minutes of the half: Islam Slimani, Andy King, Fuchs and Marc Albrighton.
After Pawson blew the half-time whistle numerous visiting players, and Ranieri, approached the official, who was surrounded by security personnel.
Ranieri, the veteran Leicester manager, had to be hauled away by his players, while City coach Mike Stowell restrained Slimani, who was leading the players' protests.
It was a scene that could yet lead to disciplinary action by the Football Association.
In addition, furious Leicester supporters, gathered in the corner of the ground where the tunnel is situated, had to be held back by stewards as Pawson headed into the dressing room.
It appeared that objects were also thrown in the officials' direction.
On the field, the opening goal followed 11 minutes after Vardy's dismissal when Simpson slid in to try and intercept Bojan's cross from the left-hand byline and handled.
The Spaniard took the resulting penalty himself and slotted the ball low into the bottom-left corner of Kasper Schmeichel's goal.
Stoke doubled their lead in injury time when Giannelli Imbula received a short free-kick and drove a powerful shot against the post and off Schmeichel, allowing Joe Allen to tap into an open goal.
Earlier, Schmeichel had dived sharply to the foot of his post to keep out Jonathan Walters's low shot after just five minutes.
But Leicester, with Vardy looking sharp on the counter-attack, looked just as likely to open the scoring.
The England forward volleyed wide from Albrighton's long ball, then started a counter-attack that allowed Riyad Mahrez a run at goal from which he tested Lee Grant with a driven shot.
King's cross was then met by Robert Huth, whose powerful header was tipped over the crossbar by Grant.
Slimani beat Ryan Shawcross to King's long pass on 23 minutes, taking the ball in his stride and forcing Grant into another solid piece of goalkeeping.
A mistake by Erik Pieters gifted Leicester the ball in his own half and allowed Mahrez another shot at Grant.
Huth was cautioned, along with Stoke's Glen Johnson, early in the second half, becoming the visitors' sixth booking in nine minutes either side of the interval.
The game might have been put completely beyond their reach just before the hour when Diouf's deep cross found Walters, whose goal-bound header was well saved by Schmeichel.
Leicester, to their credit, halted their decline and ill-discipline as they sought a way back into the contest.
In the 74th minute, substitutes Demarai Gray and Leonardo Ulloa combined to give Ranieri hope when their respective first touches led to a goal.
Gray crossed from the left and Ulloa rose impressively to head goalwards. Shawcross cleared, but the goal-line technology confirming the ball had crossed the line.