Tiger Woods isn't the only one back in the swing of things ... so is mistress numero uno Rachel Uchitel ... who busted out her tiny bikini and her new man for a beach day in Miami yesterday.
Rachel says her 25-year-old BF Matt Hahn is, "The best thing that's happened to me in as long as I can remember."
Apparently, she's having trouble remembering the time she got a $10 million check from Señor Woods.
Rachel Uchitel -- Bikini Makeout Session
4/12/2011 1:40 PM PDT BY TMZ STAFF
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