With Jonny Evans and Wesley Fofana available, manager Brendan Rodgers fielded both centre-backs as part of two changes to the XI that beat Brentford prior to the international break. Daniel Amartey, who helped Ghana seal a spot at the 2022 FIFA World Cup on Tuesday, and Turkey's Çağlar Söyüncü made way.
Backed by the raucous roar of 3,167 City fans, the Foxes started in impressive fashion. Academy graduate Harvey Barnes skipped passed Diogo Dalot with only 65 seconds on the clock and earned a free-kick. Maddison provided the delivery for Barnes, who flicked a header onto the roof of the net.
A first yellow card of the game arrived on five minutes, when Luke Shaw scythed down James Justin on Leicester's right wing. In came another set-play from Maddison, however Fofana couldn't quite get there. The France Under-21s defender then resumed defensive duties by blocking a pass aimed at Anthony Elanga.
A brace of Barnes attempts flew off target while Maddison had to intervene on 13 minutes to dispossess Jadon Sancho. Not long after, Timothy Castagne was able to clear the ball away from the head of Scott McTominay, who met Elanga's cross from the wing. Fofana went into the book not long after for a foul on Elanga.
Captain Kasper Schmeichel's first save of the game arrived midway through the first half, with the Denmark stopper - now capped 80 times for his nation after the latest round of international matches - holding onto Paul Pogba's goal-bound header.
The hosts were then gifted a goalscoring opportunity when Fred intercepted a pass in the Manchester United midfield and Bruno Fernandes was played in. The midfielder had a strike saved by the left leg of Schmeichel, while a booking for Youri Tielemans followed after he arrived late on Fernandes during a Man Utd attack.
Although the Red Devils were growing into the game, City remained fluid going forward. A combination between Tielemans and Justin forged an opening for Nigeria's Kelechi Iheanacho, who curled wide with his left foot from 20 yards out. Relief for Ralf Rangnick's side.
The quality of delivery from Maddison continued to cause havoc among the United backline, with Barnes volleying off target after getting the run on Dalot around six yards out. A one-two between Elanga and Sancho broke down, with Schmeichel gathering, before Fofana diverted Shaw's cross from the left behind for a corner-kick. Goalless at the interval, with both sides mustering up opportunities to take the lead.
A neat move from City at the start of the second half signalled their intent, although former Fox Harry Maguire's outstretched leg prevented Justin from bending the ball into the feet of Iheanacho. A heavy tackle from McTominay on Maddison then resulted in a yellow card for the Scotsman.
Schmeichel was alert to Fernandes' header on 54 minutes, while a crowd of Foxes halted Elanga's effort and Dalot lifted over for the host side. Barnes then darted into the box, nutmegging Dalot in the process, only for his run to be stopped by Maguire.
Leicester's next attack was a profitable one. Tielemans and then Kiernan Dewsbury-Hall made tackles in midfield before Maddison whipped a delightful pass into Iheanacho, who was on hand to head home at the far post to spark jubilant scenes in the away end as he netted his eighth goal of the season in all competitions. Amartey replaced Evans in City's first substitution before the game resumed.
United were level almost immediately, though. Schmeichel saved well initially from Fernandes, but Fred raced onto the rebound and restored parity with approximately 25 minutes of normal time remaining.
A golden chance to restore City's advantage fell to Iheanacho, who latched onto Sancho's loose back-pass, but he was unable to guide his chipped attempt on target. David De Gea then pulled off an incredible save a minute later as he got his fingertips to Fofana's header from a Maddison free-kick. Few wearing Foxes colours could believe the net didn't bulge.
City were dominant in possession and thought they had got their reward on 80 minutes. The Foxes probed and probed, and when Iheanacho hustled on the edge of the area, he located Maddison, who slammed beyond De Gea. However after a check from VAR, a foul by Iheanacho on Raphaël Varane in the build-up chalked off the No.10's strike.
Rodgers' men were not content with a point and set about claiming a winner. Tielemans drove into the palms of De Gea from distance. At the other end, Leicester were doing their best to keep the Red Devils at bay.
After the fourth official signalled five minutes of added time, the introduction of Patson Daka in place of goalscorer Iheanacho followed, while Hamza Choudhury replaced the excellent Papy Mendy after the Senegal midfielder picked up a knock.
Into injury time, Sancho sliced wide, a move from Justin broke down on the right flank and Elanga and substitute Marcus Rashford collided in the City box, before Justin slide in to block an Elanga cross and Schmeichel gathered from the resulting corner. All over in Manchester, where the Foxes could have taken all three points. They extend their unbeaten run against Manchester United to five games in the process.
Major moment
After Fred had cancelled out Kelechi Iheanacho's opener within a matter of minutes, City remained in the hunt for a victory. They looked to have earned one when James Maddison converted from Iheanacho's pass, but VAR interjected and the Foxes had to settle for a point.
Who impressed?
Speaking on LCFC Radio's Matchday Live, 2000 League Cup winner Gerry Taggart said: "I've got to mention Wesley Fofana, I thought he was excellent, Jonny Evans as well. For Kiernan Dewsbury-Hall, it was another great experience for him. Harvey Barnes at times showed glimpses, and James Maddison as well at times was sublime. At the end of the day, if you're going to get your team on the scoresheet, you've got to make brave decisions and that was a brave header at the back post from Kelechi Iheanacho. That's why he gets my Man of the Match."
Where do we stand?
After matchday no. 28 of the 2021/22 Premier League season, Leicester are now ninth in the standings.
Coming up...
Leicester City will contest the first leg of their UEFA Europa Conference League Quarter-Final tie with PSV Eindhoven on Filbert Way this Thursday (8pm kick-off). The Foxes then host Crystal Palace in the Premier League on Sunday (2pm kick-off).
The details...
All times BST.