Arsene Wenger's £15 million signing from Zenit St Petersburg has exploded onto the Premier League scene scoring six goals in 10 league outings, including four against Liverpool at Anfield.
And he gained further plaudits at Fratton Park after wagging his finger at official Lee Mason's decision to penalise Sean Davis' challenge on him inside the danger-zone.
Despite the playmaker's honesty, the penalty stood and Nicklas Bendtner successfully converted it to hand the visitors a 2-0 lead.
But Walcott has since admitted he was quick to teach Arshavin - who captained the side at Portsmouth - about the dark side of the English game.
"I saw Andrey doing it and I ran over to him, because if you're 1-0 up away from home and the referee's given a penalty you don't want to tell him it's not one," he said in the Daily Telegraph.
"So I grabbed him and said not to worry about it, I know it's not nice but if you want to win a game you need to take these things.
"It just showed what an honest guy he is, but when you're going for the win I suppose you need to do the dirty things.
"We'd had a penalty shout with Carlos [Vela] earlier so I think these situations just even themselves out."
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