David Silva picked the pocket of Schalke defender Salif Sane before squaring for Aguero inside 18 minutes, but two quickfire penalties from Nabil Bentaleb turned the tie on its head before the break.
The former Spurs man equalised from the spot after Daniel Caligiuri’s vicious drive was handled by Nicolas Otamendi.
And the hosts found themselves in front when Fernandinho was judged to have brought Sane down inside the area, with Bentaleb once again making no mistake from 12 yards.
Things then went from bad to worse when Otamendi was sent off with 20 to play after receiving a second yellow card for a foul on Guido Burgstaller just inside the City half.
But Guardiola’s men rallied, and Leroy Sane hauled us level with an inch-perfect free-kick against his former Club with just five minutes of normal time to play.
And the comeback was complete when Raheem Sterling latched on to Ederson’s ball over the Schalke defence before finishing beyond Ralf Fahrmann at the death.
Relive a memorable Champions League victory via the video above…
