Manchester City progressed to the Carabao Cup final despite losing 1-0 to rivals Manchester United at the Etihad Stadium on Wednesday.
Nemanja Matic scored the winner but he was later sent off in the second half as City went through 3-2 on aggregate to set up a Wembley final with Aston Villa.
Raheem Sterling thought he had equalised just before half time but his goal was correctly ruled out for offside.
City appeared nervous after the break but Sterling missed a golden chance from a counter attack after 59 minutes when he went past De Gea but blasted the ball over the bar.
Matic was sent off with 15 minutes remaining and although Aguero had another goal ruled out for offside, City won the tie despite losing on the night.