The England winger has been pleading for the central striker's role for some time and, playing in his new position, Walcott proved he has what it takes to fill the boots of the London club's all-time top scorer Henry.
"He can play through the middle. I am convinced of that," manager Arsene Wenger told reporters after Arsenal climbed to fifth in the table, 16 points behind leaders Manchester United.
"He can only get stronger there. He has done very well and it just typifies what I think he can do."
Walcott's second effort was a powerful close-range strike into the roof of the net but it was his hat-trick goal that had the stamp of Henry at his best.
He bowed and clapped all corners of the stadium while cries rang out of 'sign him up, sign him up, sign him up'.
"I think he loves the club and the club loves him," said Wenger. "My desire is to extend his contract - I think he belongs here and hopefully we can do it."
"I believe Theo takes advice from Thierry," said Wenger. "It's good when you need to talk to someone who has played in there [as a central striker]."
"I've always said that I'm a striker," said the former Southampton winger who wears the same number 14 jersey Henry used to parade. "I'm not saying I want to play there all the time but it's an option for me and the team.
"It was a manic game today, it was so open and that played into our hands. Newcastle have got some top quality players and they play some good football at times but as soon as it went to five we could see some of their heads dropping."
