Goals either side of half-time from Josh Gentles and Findlay Curtis put Rangers in a commanding position, but the home side rallied to turn the game on its head in ten second half minutes.
Indeed, the young Gers travelled with only one player aged older than 19 in the matchday squad, giving the nod to 2007-born duo Josh Gentles and Calum Adamson in the starting lineup.
There were also notable firsts at full-time as Alfie Halliwell, Connor Campbell and Callum Burnside, who have spent this season with the Under-18s, made their first outings for the B Team.
Played in the shadows of the Bosuilstadion, which hosted Rangers’ 4-3 victory over Royal Antwerp in the Europa League knockout stages in 2021, the young Gers began with a spring in their step.
The first opportunity of the contest arrived for the away side on ten minutes when a direct kick from Mason Munn found Gentles who drove into the Antwerp half. Releasing Archie Stevens to his right, the 18-year-old advanced menacingly towards goal but the damage was stifled before the Englishman could fashion an effort at goal.
However, the visitors found the all-important opening goal just three minutes later. Assisted by Bailey Rice, the clinical Gentles found the back of the net when he smashed an unstoppable effort beyond the Antwerp goalkeeper.
Rice then very nearly turned goalscorer when his dipping free-kick worried Delaporte in the hosts goal, although the Antwerp No.1 was able to collect the ball.
Rangers continued to create chances aplenty as the first half wore on, with Paul Nsio rising highest from a Rice delivery that he could only steer into the grateful hands of the Antwerp stopper.
Half-time brought a triple substitution from the Light Blues as Halliwell, Blaine McClure and Chris Eadie entered proceedings.
The latter instantly combined with Findlay Curtis two minutes into the second period, but Antwerp were able to smother the danger as Eadie lurked with intent inside the penalty area.
Rangers doubled their advantage moments later as Curtis made the difference in the final third, linking smartly with Stevens before lashing his finish beyond the Antwerp goalkeeper.
Curtis was again involved with a little over 20 minutes remaining when Connor Allan advanced down the right and picked out the 17-year-old with a delivery, but the midfielder could not find the finish to match.
The home side made the Light Blues pay for their profligacy two minutes later when they pulled a goal back, before they restored parity five minutes later to leave the game in the balance.
Nsio then sent a long-range effort wide of the target as the Light Blues stepped up their recovery in search of a winning goal.
However, the Belgian side completed the turnaround – all in a ten-minute spell – to leave the young Gers with an uphill climb.
Rangers poured forward in search of a leveller, going close via a Kristian Webster header, but it was to be in vain as David McCallum’s side fell to defeat.
ROYAL ANTWERP: Delaporte, Aertbelien, Gillot, Gielkens, Davis, Darcon, Degallaix, Van Helden, Goossens, Godelaine, Egah
Subs: Hamdaoui, Schelfout, Courtens, Tuypens
RANGERS B: Munn (Halliwell, 45), Allan, Webster, Grant (Wyllie, 57), Hutton (Campbell, 57), Rice, Adamson (McClure, 45), Nsio, Stevens (Burnside, 66), Lovelace (Curtis, 18), Gentles (Eadie, 45)