Jerry Yates put the visitors ahead with a composed finish five minutes before half time, but a Jonathon Margetts brace saw the Iron come from behind to record victory on Wednesday afternoon.
Following their triumph in the reserves over Gateshead at Roundwood Sports Complex last week, Garreth Barker’s youngsters once again deputised in the Final Third Development League making the trip following the first team’s draw at Craven Cottage.
The hosts were first to set their sights on goal at Glanford Park when Zac Thompson’s curling free kick from 20 yards went up and over the wall, before cannoning off the upright and away from danger.
Yates provided the visitors first threat on the half hour mark when he powered a header at goal, from close range only to be denied by a superb reaction save from Sam Slocombe in the Iron goal.
A young Millers outfit continued to press and were rewarded for doing so when Yates broke the deadlock five minutes before the interval.
Slocombe produced a good initial save to deny Yates but was powerless to resist as the forward kept his cool to slot home the rebound to ensure the Millers went in ahead at the break.
Half-time: Scunthorpe United 0 v 1 Millers
The hosts appeared revitalised after the restart and applied some early pressure to Scott Loach’s goal.
Trialist Jonathon Margetts was the first to test the former Watford ‘keeper after just three minutes of the second half had elapsed when he side-stepped his marker and fired a shot at goal which Loach saved smartly.
Margetts looked keen to prove himself in Iron colours and came close again with an attempted lob over Loach following a clever pass from Levi Sutton which the Millers’ stopper once again was equal to.
The Hull City man finally got his reward on 68 minutes when he produced a fine curling effort which found the top corner from 20 yards to restore parity at Glanford Park.
Scunthorpe and Margetts doubled their goal tally for the afternoon just minutes later when the Edenthorpe-born forward found himself in on goal again and this time successfully lifted the ball over the onrushing Loach to put the hosts ahead.
The Millers had a golden opportunity to equalise 15 minutes from time when Darnelle Bailey-King raced in behind the defence, only to be thwarted by the heroics of Slocombe who produced a matchwinning save to deny him one-on-one and secure maximum points for Scunthorpe.
Full-time: Scunthorpe United 2 v 1 Millers.