The Royal Blues appeared to be cantering to a second straight win in Group B, but the Senegalese hitman popped up with just minutes remaining to stun the home side
Karim Ait-Fana opened the floodlights early in the first half, before Julian Draxler restored parity and earned a penalty for the Bundesliga outfit, which Klaas-Jan Huntelaar netted. However, Souleymane Camara emerged at the death to allocate a share of the spoils.
A refreshingly free-flowing contest was witnessed at the Veltins Arena, with both sides not afraid of playing attacking football. Yet it was the Germans who seemed the most dominant side, as they strived to make home advantage count on the night.
But it was the visitors who took the lead in Gelsenkirchen. A mazy run saw Remy Cabella spray the ball out wide to Ait-Fana, who wrong-footed Atsuto Uchida with his first touch and floated a beautiful curling effort into the bottom right corner.
Not before long, though, Schalke came charging back. A raking through pass from Klaas-Jan Huntelaar was latched onto by the onrushing Draxler, and the German prodigy's burst of pace saw him round the goalkeeper and tap into an empty net for the equaliser.
Huub Stevens' side suddenly began to look more comfortable in possession, but that did not deter the open nature of the match, as Younes Belhanda could have put Montpellier back in control, if not for his powerful long-range strike whistling just wide.
Teemu Pukki and Huntelaar also came close on occasions in the first half, and the action only intensified after the break. Kyriakos Papadopoulos and Pukki tested their opponents' resolve moments into the restart, before the hosts soon won a penalty.
A superb run from Draxler was stopped in its tracks by Garry Bocaly, who conceded a penalty and was given his marching orders not long after. Huntelaar stepped up and made no mistake from six yards out to give the hosts the initiative.
Montpellier looked flat after the defender's dismissal, and the remainder of the encounter was played out by Schalke, despite the arm injury incurred by star man Draxler.
Still, visiting coach Rene Girard needed Geoffrey Jourden on top form in the latter stages of the tie to deny Huntelaar and Ibrahim Afellay from furthering the Germans' lead. The Dutch striker then made a complete hash of grabbing the third, as he dragged a shot wide.
But Huub Stevens would have been pulling his hair out at the final whistle as, on the 90th minute, Camara received the ball on the edge of the box and fired a stinging shot past Lars Unnerstall.