While Kaba Sherif's magnificent 32nd-minute opener was curtailed by Jack Sparkes after the restart, a point is enough for the Foxes to remain second in Group D with one game to play.
There were two changes to City’s line-up after a 1-0 defeat by Derby County in Premier League 2, as Layton Ndukwu and Calvin Ughelumba came in for Kiernan Dewsbury-Hall and Luke Thomas.
Exeter, though, started brightest as Ben Seymour crossed into the box, missing everyone in the middle, but it filtered through to Sparkes, whose attempt from 16 yards out clipped the bar.
In the 15th minute, Tyrese Shade did well to win a corner and Ndukwu’s curler met Callum Wright’s head in the six-yard box, but the former Blackburn Rovers youngster sent his effort wide.
Another Ndukwu corner just five minutes later, from the opposite left side, also caused havoc in the home side’s penalty area as Louis Ramsay half-volleyed a clearance at goal.
While Felix Norman was able to get a hand to it, the ball landed for Admiral Muskwe, but the Zimbabwe senior international was unable to make the required contact with it from five yards out.
City deservedly took the lead in outstanding circumstances in the 32nd minute. A third corner came out to Kaba Sherif - who didn’t hesitate to go for goal on the volley from 25 yards.
The 20-year-old’s effort was audacious, but had the quality to match its ambition as it flew into the bottom corner, giving Norman no chance in the Exeter goal.
While the first half passed without any further incident, it wasn’t long after the restart before another talking point was to dominate the conversation in the stands in Devon.
Defender Sam Hughes, making his second start as captain since returning from a lengthy back injury, was adjudged to have fouled Sparkes in the area.
Although Viktor Johansson did brilliantly to keep out Seymour’s initial penalty, Sparkes raced into the box to capitalise on the rebound and restore parity on the scoresheet.
With 54 minutes on the clock, meanwhile, Calvin Ughelumba galloped down the left flank and, after a mix-up by the hosts in defence, it dropped to Muskwe, who struck the base of the post.
In the latter stages, City's pressure continued and they were desperately unfortunate not to win it when Kaba Sherif's low drive from distance was cleared off the line.
Leicester kept the ball in play, though, and it fell to Hughes in the centre, but his effort was too high and was sent over by the former Chester man.
Within just four minutes of added time, the visitors were reduced to nine men as substitute Kairo Edwards-John was dismissed for a challenge off the ball, while Wright earned a second yellow card.
However, despite some late pressure from Exeter, the Foxes were resolute in testing circumstances to make sure of an important point.
Who impressed?
While Lamine Kaba Sherif’s opener for the Foxes will undoubtedly attract deserved acclaim, the 20-year-old central midfielder’s all-round performance was also noteworthy.
In Kiernan Dewsbury-Hall’s absence, the visitors desperately needed some nous in the heart of midfield, something Kaba Sherif has provided for the past two seasons for the Under-23s.
Where does it leave us?
A point puts Leicester's youngsters in a commanding position to seal safe passage to the knockout phase as runners-up in Group D, with six points and a goal difference of +2.
Third-place Exeter, on six, have now completed their fixture programme on a goal difference of -4, meaning only a heavy defeat for City at Nottingham Forest next week would see placings change.
Forest's first-place position, meanwhile, is also confirmed, following their gathering of a healthy points tally of 12 in four games. Norwich, on the other hand, are bottom with two points.
Coming up…
City next head to the Impact Arena to contest their final group stage fixture with leaders Nottingham Forest next Thursday (1pm GMT kick-off).
That clash will be available for Foxes fans to watch - for free - on LCFC TV from 12:45pm GMT on Thursday.
The details…
City: Johansson, Ramsay, Hughes, Pascanu, Ughelumba, Kaba Sherif, Shade, Wright, Loft (Edwards-John 74'), Ndukwu (L. Thomas 65'), Muskwe
Subs not used: Bramley, Heaven
Goal: Kaba Sherif 32’