Javier Hernandez scored the only goal of the game to give United a 1-0 win at the Mestalla.
“We come here and set our stall out to make sure we didn’t concede,” Ferdinand told ITV.
“We tried to hit them on the counter and in the first half we contained them but we didn’t offer much going forward.
“But the two subs combined with Nani and it was a great goal.”
He continued: “The win is definitely a confidence booster. It’s been well documented we let points slip in recent games, but we’ve done well tonight. To get a win in Spain is good.”
Ferdinand also heaped praise on Mexican striker Hernandez.
“He (Hernandez) is a fantastic lad, he’s got a great attitude and he wants to learn. He always stays late in training and we’ve got players who can come on and make a difference,” the England international said.
