FC Halifax Town recorded a sensational 3-0 win at Leyton Orient to move up to second place in the National League.
Adam Morgan and Tom Denton put Town into a barely-believable 2-0 half-time lead before Matty Kosylo's penalty capped a magnificent night for The Shaymen; surely their best result yet under Billy Heath.
If Town were in the nose-bleed territory of sixth before kick-off, Morgan's goal put them joint-top of the league as The Shaymen made the perfect start, with the striker turning sharply eight yards out to fire high into the net left-footed.
It didn't take long for Town's lead to look fragile though, with Matt Harrold missing a sitter six yards out before Romuald Boco squandered two clear chances inside the penalty box.
Top-scorer Macauley Bonne then had a shot saved before his flick header went across goal and wide from a corner as Orient responded well to falling behind.
Denton found the net as the Town man met a flighted free-kick at the far post with a bullet header to double the visitors' lead as the game reached eyebrow-raising proportions.
Jobi McAnuff curled a fantastic shot off the post shortly before half-time, but by now that was against the run of play, as emphasised by the smattering of boos from the home crowd that greeted the half-time whistle; music to Billy Heath's ears.
The game was put beyond doubt when Kosylo sent Grainger the wrong way from the spot to the sound of stunned silence - apart from the jubilant 153 Town fans - after Morgan had been fouled in the box.
Leyton Orient: Grainger, Caprice, Sendles-White, Clark, Widdowson, McAnuff, Lawless, Boco (Mooney 61), Clay, Harrold (Koroma 87), Bonne. Subs not used: Sargeant, Happe, Ochieng.
Halifax: Johnson, Wilde, Garner, Brown, McManus, Macdonald (Tomlinson 69), Hotte, Oliver, Kosylo (Charles 89), Morgan (Moyo 81), Denton. Subs not used: Lynch, Nicholson.