Anthony Georgiou brought us back on level terms six minutes from time when he cancelled out a first half opener from the Saints’ Marcus Barnes.
The visitors had other ideas, though, as Jake Hesketh crashed home a low shot three minutes later.
But with time running out, Miller – who had missed a penalty in the first half – popped up in the area to force the ball home and ensure the match ended 2-2.
Having already secured top spot in the Barclays Under-18 Premier League southern division, we looked to take control of the game from an early stage with Channing Campbell-Young drifting a shot into the arms of goalkeeper Chris Johns and Daniel Akindayini forcing the visiting stopper to palm the ball out three minutes later, with Emmanuel Sonupe off-target from the rebound.
Goalkeeper Harry Voss made a fine save low to his right to keep out a fierce header from Kyle Clinton, but he couldn’t prevent Southampton from taking a 12th minute lead. Ryan Seager ferried the ball out to Barnes to the left-of-centre, who fired low into the net from 18 yards out.
Southampton looked more threatening as the first half went on, Seager clipping the crossbar with a right-footed free-kick and Hesketh testing Voss with a rising shot.
Three minutes before the break we got the chance to restore parity when Miller fed Daniel Akindayini, who was bundled over in the box by Clinton. Miller took the penalty, but Johns saved low to his left to ensure the Saints went in at the break a goal to the good.
Sonupe scooped a loose ball over the bar from close range after good build-up play by Akindayini as we sought a leveller four minutes into the second period, the wide player also seeing a left-footed effort blocked by a defender after cutting in from the right.
Just beyond the hour mark, the lively Anthony Georgiou tricked his way into the box on the left, his attempted cross being deflected into the path of fellow substitute Ryan Loft – but the young forward could only hook the ball the wrong side of the woodwork as it came to him at an awkward angle.
Voss saved with his legs from Seager at the edge of his area and Hesketh’s shot was easy for the stopper as the Saints tried to extend their lead.
Loft only partially met Sonupe’s cross at the other end, while Miller’s free-kick was comfortably caught by Johns.
We finally made a breakthrough six minutes from time when Johns palmed Sonupe’s right-sided cross back into the danger zone, with Georgiou there to tuck home the rebound.
But any idea that the equaliser would be the last of the goalmouth action was quickly nullified when Hesketh collected a loose ball in midfield and crashed a low shot into the bottom corner of our net from 25 yards with 87 minutes on the watch.
And there was still more drama to unfold as Miller netted in the third minute of stoppage time to salvage a point. Johns got his hands to Miller’s shot from Sonupe’s deflected cross, but he was unable to keep it out as we once again hauled ourselves back level.
Spurs: Voss, Campbell-Young, Muscatt, Amos, Maghoma, Carter-Vickers, Sonupe, Stylianides (Owens 62), Akindayini (Loft 56), Miller, Daly (Georgiou 56). Substitute (not used): Ogilvie.