The England Under-21 boss has lavished praise on the way Walcott handled starting the Spain game from the bench.
The pacy forward replaced winger Adam Johnson and his forward and probing runs were difficult to track. He also provided England's second goal, neatly assisting Aston Villa flanker James Milner.
"I must mention at this stage Theo Walcott's attitude," Pearce was keen to stress to a press conference. "We spoke before the game about how he answers not being in the starting line-up. You know, it's difficult for him to understand how he's played for the seniors and then he didn't start here.
"The only way you answer a managerial team selection is to put in a performance of both attacking and defending that he did and credit to him, but I expected no less from him. I felt with the game going to be being stretched in the second half he'd have an impact - he proved me right.
"But then I know Theo and I know what he's capable of, and little Adam Johnson had done nothing wrong for me. He took the sting out of the Spaniards to start with and enabled Theo to come on and put on the virtuoso show that he did."
Alan Dawson, Goal.com