The goalkeeper’s shutout at Villa Park was his seventh in the league this season and his 169th since arriving in England during the summer of 2004.
Walcott believes Cech has “changed us completely in the back four” since signing this summer.
“From when we signed him, we all knew how good he was [after] what he achieved at Chelsea,” Walcott told Arsenal Player. “On a personal level, for him it’s great.
“He’s changed us completely in that back four. He’s a talker, he believes in us all.
“That’s why he wanted to join us and having with that presence behind you is always nice to have. He’s very commanding, he’s a leader in the dressing room as well, he always likes to talk.
At the other end of the pitch, Olivier Giroud continued his fine recent record by opening the scoring. Walcott says his fellow forward is a “dream to play with”.
“It’s not just his goals, it’s his general play and everything about him,” he added. “The way he holds the ball up, he blocks it and defends it, and he works hard from the team from defensive corners and everything.
“He’s in great form at the moment. He’s a dream to play with and he makes our job a lot easier. As soon as I won the penalty, I just knew that he would score.
“Confidence is streaming through him and you want that in the busy Christmas period. You want players that are on form and he’s definitely one of them.”