Lampard – who will try to convince Giroud not to walk away in January – suggested the 34-year-old could now force his way into his plans for Spurs.
“He does things like he does tonight, he’s great,” he told BT Sport after the 2-1 win. “It wasn’t just his goal when he came on, but his hold up play and physicality.
“I have a problem because Tammy (Abraham) is playing well and Olivier in the restart was incredible. I have two players fighting for the position, but it’s a good problem.”
Giroud’s future remains in doubt, with the forward concerned about losing his place in the France squad ahead of the Euros.
Lampard has promised him minutes and plans to hold talks with him before the January window opens.
He added: “The thing behind the scenes and what everybody thinks from the outside is what a great professional he is and how highly regarded he is by his teammates and by myself.
“So for him to get a goal – you saw the reaction of his teammates. He is so professional in how he trains and looks after himself that age isn’t even a factor.
“I think he’s getting better with age, if anything, with how well he looks after himself, so he offers a lot for us.
“With the schedule coming up and the way we play means I will rely on players.
“Thankfully for me he is a player who always keeps the right attitude if he’s not playing regularly, I know I can call upon him as I did today.”