Iago Aspas scored twice, with Williot Swedberg and Tasos Douvikas also hitting the back of the net.
He said: "Very happy and content. It is a marked day in my life as it is my first victory here. But, beyond Claudio, it is important for all of Celticism. It has been a party, everyone has enjoyed it. They deserve it, they have helped us a lot.
"We were able to make many scoring chances after stealing and running. I am happy to have more records and to be less predictable. I don't like repeating eleven. The group's work was brutal. The classification indicates that we depend on ourselves and "We have to focus on our work."
On Aspas, he said: "He is fundamental for us, he is an example of involvement and work on a daily basis. Sometimes, he does not get the reward he deserves. I am happy for him. He is the best in the club's history."
On Douvikas and Swedberg, Giraldez added: "Tasos has to take that continuity, he gives us goals and power. Williot is intelligent and complete."