The Millers are promoted! On-the-whistle report: Gillingham 0 Rotherham United 2

Georgie Kelly fired in a debut goal only minutes after coming on as a late substitute to clinch a 2-0 triumph that saw the Millers finish in second place.

Rarmani Edmonds-Green had scored in the first half against a Gills side who suffered relegation as a result of their defeat.

Rotherham's recent wobble became a thing of the past as hundreds of Millers fans raced on to the pitch in celebration at the final whistle.

The triumph brought a hat-trick of third-tier promotions under manager Paul Warne.

Well over 2,000 followers had made the long journey to Kent and they were in full voice long before the start.

With kick-off minutes away, manager Paul Warne came to applaud the massed ranks of red and white which served only to ramp up the volume level even further.

The Millers were on the front foot from the start and Ben Wiles and Michael Ihiekwe sent headers wide of the Gillingham goal within the first seven minutes.

Edmonds-Green looked like he was about to open the scoring on the quarter-hour mark as he made contact with the ball from close range but Rotherham-born goalkeeper Aaron Chapman pulled off a sharp reaction save.

Six minutes later, Ihiekwe missed again with another header while at the other end Ben Reeves bent in a free-kick that gave Viktor Johansson little trouble.

The home side were fighting to avoid relegation and were mounting a strong defence, packing their penalty area whenever Rotherham threatened.

But their resistance was broken on 34 minutes when Ihiekwe rose highest at a corner and Edmonds-Green applied the final touch.

Flares and celebrations were still going off in the away end when Michael Smith wasted a golden opportunity to double the lead, shooting horribly wide after a searing run and supply from Chiedozie Ogbene.

Gillingham nown had to come out and attack and the Millers were served a warning right on half-time when Ben Thompson clattered the bar for the home side with a chance he should have put away.

Rotherham were unchanged for the third match in a row, which meant there was no place in the squad again for wantaway striker Freddie Ladapo.

Ogbene was paired up front with top scorer Michael Smith and Wes Harding took the Republic of Ireland flyer's usual wing-back spot on the right flank.

Warne's men had to weather a spell of Gills pressure at the start of the second half before they broke out for Ogbene to fire wide.

They were immediately on the defensive again and were relieved to see Max Ehmer fail to keep his back-post attempt down.

With the clash starting to go end to end. Wiles had a shot saved and Ogbene headed the rebound over as the Millers played towards their bank of supporters.

The Millers were managing to weather a severe test and Wiles unleashed a piledriver in the hope of easing the tension but Chapman pulled off a flying stop.

As time began tick down, Ihiekwe headed straight at the keeper who then beat away a vicious Wiles volley.

Kelly had been introduced for his debut and his flicked header was headed home by Richard Wood only for the offside flag to be raised.

Rotherham needn't have worried. In the 89th minute, the new boy took possession of Ogbene's pass and thumped the ball past Chapman for a goal nine minutes into his Millers career.

Joy for him, even more joy for the entire team a few minutes later when promotion was confirmed.

Gillingham (5-3-1-1): Aaron Chapman; Ryan Jackson, Conor Masterson (Dan Phillips 74), Max Ehmer, Jack Tucker, David Tutonda (Gerald Sithole 87); Olly Lee (Mustapha Carayol 67), Ben Thompson, Stuart O'Keefe; Ben Reeves; Vadaine Oliver. Subs not used: Pontus Dahlberg, Havey Lintott, Christian Maghoma, Josh Chambers.

Rotherham (3-5-2): Viktor Johansson; Rarmani Edmonds-Green, Richard Wood, Michael Ihiekwe; Wes Harding, Ben Wiles, Dan Barlaser, Ollie Rathbone, Jordi Osei-Tutu (Joe Mattock 67); Chiedozie Ogbene, Michael Smith (Georgie Kelly 80). Subs not used: Josh Chapman, Jamie Lindsay, Hakeem Odoffin, Tolaji Bola, Josh Kayode.

Goals: Edmonds-Green 34, Kelly 89 (Rotherham).

Referee: Samuel Barrott (West Yorkshire).

Attendance: 8,542 (2,255).