Ederson thwarted Adama Traore's one-on-one attempt before Doku scored City's third goal in the thrilling 3-2 victory.
"I don’t think there’s any doubts about how good he is as a keeper,” said Doku afterwards.
“He’s saved us a lot, not only in this game. But he’s always there to help us, even with the ball.
“He’s a very reliable goalkeeper, as I should say.”