The Argentine scored with a header from a corner in the 71st minute after Shaun Wright-Phillips netted five minutes after the break to give City the lead.
"I was hoping that by playing Carlos that it would be an opportunity for him to get off the mark and was delighted that he did so," Hughes said.
"Carlos is a quality player with great intelligence. He makes the right runs time and time again.
"He is working very nicely with Emmanuel Adebayor."