A spectacular 20 yard strike from substitute Brandon Potts was the difference between the sides on a red hot afternoon at Parkgate, with Academy Manger Garreth Barker marshalling the side.
The Millers fielded a youth team for the Final Third Development League clash with Gateshead with just Daniel Rowe and Jerry Yates having any first-team experience.
The youthful Millers almost had the perfect start when Jerry Yates had the first real chance of the afternoon but his shot from six-yards was well blocked.
Gateshead, led by former Millers midfielder Micky Cummins, came close when Liam Thear flashed a shot just past Peter Denton’s far post.
First year scholar Darnelle Bailey-King showed glimpses of real pace down the right and his teasing centre was deflected just wide by a Gateshead defender.
At the start of the second half the Millers missed a good chance following good work by Kuda Muskwe which resulted in a cross to the back post, but Mason Warren skewed his effort wide.
Just before the hour mark the Millers had Denton to thank for keeping the game level when he saved a spot kick to deny Tom Marshall, after Denton himself had brought down Thear in the area.
Sub Adam Johnson almost scored with his first touch but his 20 yard shot was saved by Gateshead stopper Alex Baird, and moments later Warren’s free-kick arrowed just over the bar.
Late on Warren went close again with a fierce strike across goal but the Millers couldn’t breakdown a stern Gateshead defence. Just when it looked like the game was going to end goalless sub Potts hammered in a screamer from the edge of the area to win it in the final minute.
Rotherham: Denton; Lucas (Potts 75), Rowe (Peace-McDonald 81), Hallatt, Rose, Bailey-King, Fenton, Warren, Gibson, Muskwe (Johnson 61), Yates.
Subs not used: Bilboe, Shelley, B. Wiles, Smalley.
Gateshead: Baird; Morse, Allan (Mills 75), Clark (Ackroyd 62), Wilson, Thear, Briggs, Drane, Kanda, Marshall, Orrell.
Subs not used: Ure, Wilson, Perry.