I suspect it's a typo in the original, or some sort of a play on words by the author, though that's very unlikely. "Gold" makes no sense, but "golf" -- as you've supposed -- fits very well. The only other possibility is "gold tennis" as a variant of tennis. The Oxford Companion to Sports and Games, however, lists only the following varieties of tennis: Beach, Deck, Lawn, Real, Ring, and Table. "Gold" is not listed as a sport. The closest are the "Golden Gloves" boxing competition, "Golden Globe Race" in yachting, and the "Golden Slipper Stakes", an Australian horse race. But none of those fit the language or the meaning. Whereas "golf" does, perfectly.
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