Pieters produced the matchwinner with his cross-shot on Saturday.
He and Krul have been friends since playing together for the Dutch Under-17 team, and the full-back joked: "I told him I meant it.
"Everybody knows he's my best friend in football. I've known him since I was 17. It was really good to score my first goal, and a great goal as well, against him.
"We talk to each other a lot, about our personal lives as well. We support each other always and we have a good relationship. I'll keep texting him, for sure."
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