Pep Guardiola warned Manchester City cannot expect to win the Champions League if they gift their opponents goals as they did in their dramatic 3-2 win over Schalke.
City claimed a first-leg advantage in their round-of-16 tie in Germany, though only after substitute Leroy Sane's 85th-minute equaliser was followed by Raheem Sterling's 90th-minute winner.
Schalke had fallen behind to Sergio Aguero's opener, yet entered the interval 2-1 ahead thanks to a pair of Nabil Bentaleb penalties, awarded for a handball against Nicolas Otamendi and a foul by Fernandinho.