Vardy drew level with the 10-game mark established by United great Ruud van Nistelrooy when he netted at Newcastle United last week but the division's most miserly defence stood in the way of his landmark achievement.
They were breached after 24 minute as, sporting gold boots, the England striker demonstrated the coolness and precision in front of goal that are quickly becoming his trademarks to put the hosts ahead.
On the stroke of half-time, Bastian Schweinsteiger's first goal for United cancelled out Vardy's 40th in Leicester colours to temper the party atmosphere and a cagey second half threw up few clear-cut chances.
The draw means Manchester City sit ahead of Leicester at the Premier League summit on goal difference, with United a point further back in third.
Shinji Okazaki replaced Leonardo Ulloa to join Vardy in the Leicester attack, while Paddy McNair and Michael Carrick returned from injuries amid four changes made by United boss Louis van Gaal.
The home faithful roared in response to Vardy's every touch and his first opening came in the 13th minute when Carrick carelessly presented possession to his England team-mate, who found N'Golo Kante for a shot that was deflected behind.
United, operating with a 3-5-2 system, were controlled and methodical in their play and Wes Morgan blocked a strike from Schweinsteiger as the half reached its midway point.
Shortly afterwards, Leicester's contrasting approach heralded an historic moment.
Kasper Schmeichel claimed a United corner and threw the ball to Christian Fuchs – the Austria full-back charging over the halfway line on a rapid break to release Vardy with a measured pass from the right.
The man of the moment scampered clear and clipped a low finish beyond De Gea before embarking on an adrenaline-fuelled celebration as the King Power Stadium went wild.
Spurred on by their raucous fans, Leicester sought to press home their advantage and Riyad Mahrez completed a delicate one-two with Okazaki to force a sharp stop from De Gea.
United threatened sparingly but, after Leicester midfielder Danny Drinkwater headed nervously behind, they had an equaliser in first-half stoppage time.
Daley Blind delivered the resulting corner into a dangerous area and Schweinsteiger shrugged off Okazaki far too easily to head home.
Four minutes into the second half, the Germany captain was afforded more space on the end of Juan Mata's free-kick but his headed attempt was too close to Schmeichel.
The first-half's earlier pattern re-emerged - United controlling possession before they were almost punished by another lightning Leicester break in the 66th minute.
Mahrez was the architect on this occasion and, with Ulloa and Vardy on his inside, he picked out the recently introduced substitute who could not match the top scorer's incisiveness as De Gea saved.
A striker experiencing contrasting fortunes to Vardy, Wayne Rooney, made way for Memphis Depay two minutes later following a lacklustre display.
Depay blazed over from close range in the 84th minute, while former non-league man Vardy did not get the chance to add another chapter to his fairytale before taking the acclaim at the final whistle.
Key Opta stats:
- Jamie Vardy has netted 13 goals in the last 11 games and is the current top Premier League goalscorer with 14 goals.
- Vardy's 14 goals make him the highest scoring Leicester City player in a single Premier League season, one above Tony Cottee who scored 13 in 1999/2000.
- Manchester United (and David de Gea) conceded from open play in the Premier League for the first time in 545 minutes.
- Christian Fuchs registered his first assist in the Premier League for Vardy's goal, becoming the seventh Austrian to assist a Premier League goal.