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Bionic Poster
His Wikipedia page actually lists that third round among his other achievements:
"Castle became a professional tennis player in 1986, after completing a marketing degree whilst on an athletic scholarship in the United States. During his playing career, he was regularly ranked number one in Great Britain. In 1986 Castle reached the third round at Queens Club. He won three tour doubles titles, and was a mixed doubles finalist at the 1987 Australian Open."
It's very odd that it doesn't mention that he reached the third round at the US Open the following year. A much more noteworthy achievement wouldn't you say?