Belgium scored an injury-time winner to prevent Stuart Pearce's England from putting one foot in the U21 European Championship play-offs.
Kelly's early goal cancelled out by late drama
Belgium scored an injury-time winner to prevent Stuart Pearce's England from putting one foot in the Under 21 European Championship play-offs and send qualifying Group Eight back into the balance.
Martin Kelly's early goal looked set to maintain the Young Lions' 100 per cent record in the group.
But a double substitution by the home side proved a masterstroke as Jens Naessens equalised 18 minutes from time and Omar El Kaddouri pounced in the dying seconds after Jordan Henderson missed a glorious chance for England.
The result lifted Belgium up to second in the table, four points behind England ahead of February's return meeting between the sides.
The manner of England's defeat was eerily similar to this summer's loss to Czech Republic, which saw them crash out of the finals in Denmark.
Hot favourites
And head coach Pearce will be hoping a similar fate does not befall his latest crop of youngsters in their last three group games.
They travelled to Mons knowing victory would leave them needing just two points to reach the play-offs after they stormed to the top of the group, scoring 16 goals and conceding just one.
England were hot favourites against a Belgium side who had won just one of their four qualifiers - against rock-bottom Azerbaijan - and knew defeat would all but end their own play-off hopes.
And it was looking that way when Kelly powered England in front after just 14 minutes with his second goal in as many games.
Pearce's side have been deadly from set-pieces this season and they took full advantage of a free-kick when Kelly got on the end of Liverpool team-mate Henderson's delivery to head home via the post.
Spectacular
Belgium responded and the woodwork came to England's rescue 10 minutes later when home captain Nill de Pauw's shot on the turn scraped the upright.
England talisman Alex Oxlade-Chamberlain was unlucky not to double his side's lead when Gregory Mertens blocked his close-range exocet.
The Arsenal winger also sent a spectacular volley over the crossbar after the dangerous Thomas Meunier was inches wide with an equally-stunning strike at the other end.
In between those chances, Belgium threw on Naessens and El Kaddouri on the hour mark, and it proved England's undoing.
The pair combined to level the match 12 minutes later, El Kaddouri squeezing in a low cross from the right as Naessens darted towards the near post and slid in the perfect finish across Jack Butland.
But England should have retaken the lead with seven minutes remaining when captain Henderson volleyed Oxlade-Chamberlain's cross straight at Koen Casteels from just six yards, a miss that was to prove costly in the final minute.
Ziguy Badibanga burst clear from the halfway line and beat Kelly to fire in a left-foot shot that cannoned back off the post, with El Kaddouri quickest to react to the rebound, slamming home from 15 yards.
