A back-and-forth opening period saw the young Gers score twice to cancel out the visitors’ penalty spot leveller thanks to a Kyle Glasgow delivery that sailed all the way in and a spot-kick of his own from captain Aiden McCallion.
The visitors posed a different problem in the second period but were forced to play the final 20 minutes with ten men when Keir Gilligan was given his marching orders for a second bookable offence.
The hosts took full advantage to seal the points when Ruaridh Hall sprung from the substitutes bench to net his first Under-19s goal in his first appearance for the side with four minutes remaining.
Assistant coach, Liam Ross, named five changes to his side for the visit of the Tayside outfit, welcoming Josh Gentles into the attack after the forward appeared for Raith Rovers at the weekend as part of the club’s loan co-operation agreement.
The game began with the Light Blues on the front foot as Ashton Scally, such an impressive performer for the age group this campaign, skipped down the left-hand side but couldn’t pick out a teammate with his delivery across the face of the six-yard box.
60 seconds later, Rangers went ahead. It was Glasgow who was the architect when he shimmied inside from the right and delivered in search of Gentles whose presence was enough to disturb the Dundee United goalkeeper as he watched the cross sail all the way into his far corner.
However, the away side responded instantly when goalkeeper Greig Thackray was penalised in the act of making himself as big as he could while attempting to deny the visitors, with the spot-kick dispatched with aplomb to restore parity.
There was no time for the Gers to lick their wounds as they soon regained the advantage themselves from the penalty spot.
A darting run from Luca Rankin from the edge of the penalty area prompted a late sliding challenge from Gilligan and it was left to McCallion, so assured from 12 yards, to step up and send Lewis Haldane in the opposite direction.
A third almost arrived for the home side just beyond the half-hour mark when Glasgow latched onto a slip in the Dundee United defensive ranks, but with only the goalkeeper to beat the teenager could not find a way past the outstretched Haldane.
Gentles was next to go close when he worked a half yard from 20 yards out, curling a dangerous effort just inches wide of the far post.
The dangerous Glasgow had Haldane scrambling just before the interval when he skipped through a succession of Dundee United challenges on the edge of the penalty area before unleashing a dipping effort that skipped wide of the target.
That would prove the 15-year-old’s last involvement as he was replaced by Cameron Fernie at the interval.
The second half saw the away side grow into the contest as a swift breakaway almost engineered a leveller, although Thackray at the second attempt was quick to close down the danger as Kai Hutchison looked to poke a finish beyond the goalkeeper.
Rangers were perhaps guilty of playing their way into trouble as a scuffed clearance at the near post prompted a strike from 10 yards out which, fortunately for the home side, flew wide.
The second half then swung on the decision to show Dundee United midfielder Gilligan, booked in the opening 45 minutes for the concession of the penalty, a second yellow card for a foul on Zebedee Lawson in midfield.
It opened up new avenues for the home side who couldn’t believe their misfortune when substitute Chris Condy headed onto the crossbar from close-range after Conor Owen nodded the ball back across at the far post.
Lawson then tested his luck after jinking inside off the right-hand side, before the all-important clinching goal arrived with four minutes to play.
A short dead ball routine was worked to McCallion who dinked a delightful cross into the penalty area where the ball broke invitingly for substitute Hall in space to open his body up and slide a delightful finish into the bottom corner.
RANGERS: Thackray, Hutton, Hynd, Owen, Scally (Young, 73), McCallion, Rankin, Glasgow (Fernie, 45), Lawson (Hall, 81), Smith, Gentles (Condy, 60)
Subs not used: McGuire, Ngwenya, Caldwell
DUNDEE UNITED: Haldane, Mudie (Smith, 69), Beverley, Buchanan, Lee, Gilligan, Leiper (Bertie, 69), Beattie, Hutchison, Welsh, Franczak (Anderson, 57)
Subs not used: Zerebecki, Joss, Shields, McHale
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