Charlie Webster put the Blues ahead in Kingston upon Thames, before McAteer levelled with a magnificent hit from the left flank. Omari Hutchinson's late first-half strike for the home side, on the other hand, was again curtailed by McAteer's stylish curler with 11 minutes to play.
Coach Ben Petty made a solitary change from the 1-0 home reverse to Liverpool midway through September, as Henry Cartwright came in for Brandon Cover in the middle. It was a 3-5-2 formation for the Foxes, with three scholars in the XI - Cartwright, Tom Wilson-Brown and Will Alves.
The opening proceedings saw both sides trade possession, with Leicester having to wait until the seventh minute for a first opening. It came as England youth international Sammy Braybrooke floated a free-kick, from 30 yards out centrally, into Paul Appiah, who sent it wide of the Blues net.
For Chelsea, Dion Rankine shot from range, but Chituru Odunze was up to the task, before the offside flag was raised. Lewis Brunt was then denied by a brave block from Braybrooke's corner, although it was the home side who would take an early lead as Webster finished first time in the area.
Hutchinson's cross was soon nodded towards the far bottom corner by Mason Brustow for Chelsea. Odunze, though, leapt across his line to make a fine, one-handed save. He had to be alert when Burstow sent a powerful drive at goal, while Rankie couldn't apply a finish to his cross later on.
With 27 minutes on the clock, a moment of magic from McAteer had the young Foxes back on level terms. Out of nowhere, the talented midfielder crossed, on the left channel, but watched on as it rocketed past 'keeper Eddie Beach and into the top corner.
Appiah's cross was then sent over the bar by Tawanda Maswanhise, but the visitors were growing into the game. Braybrooke also threaded the eye of a needle soon after, locating Maswanhise in space, but a firm block in the area denied the in-form youngster.
The Blues, though, would regain their advantage before the interval as Dylan Williams' cross was half-volleyed into the net on 39 minutes. They could have extended that lead as well when Burstow got his head onto Lewis Hall's fizzed ball across the box, but that headed effort bobbled wide.
After the break, only an excellent save from Beach stopped City from levelling as Maswanhise controlled a high ball and belted it towards the top corner. The Chelsea shot-stopper, however, did particularly well to get a hand to it. Alves' effort was then deflected behind as the visitors turned the screw.
There was real quality in attacking areas for Chelsea, though, and Hall nearly added a third with a low drive, although Brunt's shin was in the way. Another opportunity passed Leicester's youngsters by moments later, as Braybrooke's free-kick, from the angle of the area, cannoned back off the bar.
Odunze provided a reminder of his talents with a decent save to stop Benjamin Elliott's low shot, while Alves fired straight at Beach at the other end. City were throwing everything at it late on, with Ethan Fitzhugh, Terell Pennant, Chris Popov and Iestyn Hughes all coming off the bench.
They got their rewards with 11 minutes to play, too, as McAteer dashed forwards and curled it into Beach's far bottom corner to make it 2-2. It could have even ended in victory for City, with both Popov and Terell Pennant spurning clear-cut opportunities in the latter stages in Kingston upon Thames.
Major moment – Making it 2-2
City deserved their leveller, but it took a moment of real quality to secure it. Kasey McAteer, a star performer for Leicester's Development Squad in 2022/23, showcased his talents to cut inside and pick his spot at the far corner.
Who impressed? – Kasey McAteer
There was some doubt inside Kingsmeadow whether Kasey McAteer meant his opener in the first half, but there was no such scepticism about his brilliant second, which came with just 11 minutes to play. The midfielder, who spent last season on loan at Forest Green Rovers, continues to shine.
Where do we stand? – Ninth in PL2
City's youngsters climb to ninth in the Premier League 2 Division 1 standings with eight points from seven games.
Coming up – Bradford's senior side
A Papa Johns Trophy visit to University of Bradford Stadium to tackle Mark Hughes' Bradford City is next up for the young Foxes on Tuesday (7:30pm kick-off). Fulham Under-21s, meanwhile, are the visitors to LCFC Training Ground in Premier League 2 Division 1 on Monday 10 October (7pm kick-off).
The details...
City: Odunze; Appiah (Fitzhugh 64'), Brunt (c), Wilson-Brown; Wormleighton (Hughes 78'), Braybrooke, Cartwright, McAteer; Alves; Maswanhise (T. Pennant 74') , K. Pennant (Popov 74').
Sub not used: Doherty.
Goals: McAteer 27’, 79’
All times BST.
Top image: Chelsea FC.