Jennifer Lopez rocks sexy bikini top and huge hat for rowdy Vegas pool party

Jenny from the block is back!

Jennifer Lopez was ready to party when she showed up to the Carnival Del Sol pool party at Drai's Beach Club at the Cromwell Las Vegas on Sunday afternoon. The age-defying entertainer rocked a bright string bikini top with a pair of little white shorts.

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Before joining the summer festivities, J.Lo posed for pics in a huge, and we mean HUGE, hat. Lopez's longtime boyfriend Beau Casper Smart joined her on a balcony at the pool party, and the 46-year-old star let loose as she danced and grabbed the mic to speak to the crowd below her.

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Lopez looked half her age as she partied in her teeny bikini top. When ET spoke with the mother-of-two, she revealed her most important beauty secret. "Sleep is very important," she shared. "I get my seven to eight hours sleep no matter what."

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See photos from her Vegas residency: