Pierre-Yves Ngawa struck a 94th-minute equaliser as Belgium established a four-point cushion at the Group 9 summit, albeit having played two games more than their main challengers.
Serbia twice led in Gornji Milanovac, but their UEFA European Under-21 Championship ambitions were dented by an attacking Belgian side as Ngawa fired in his first goal at this level. It completed a frantic end-to-end finale that brought three scores in the last 13 minutes, visiting captain Paul-José Mpoku cancelling out Uroš Djurdjević's early effort before Aleksandar Mitrović restored Serbia's advantage. Ngawa, though, had the last word.
The result leaves Belgium four points clear of Italy and six ahead of Serbia, though the pursuing pair, who meet on Tuesday, each have two matches in hand. For Red Devils coach Johan Walem, this was "a big point for us and may mean qualification". Opposite number Radovan Ćurčić rued that "mistakes cost us in the end – we had a fantastic opportunity to win".