The Brazilian model revealed all in an interview with a UK newspaper.
She said: “A man must know what to do to make me happy- Justin did all that and more.”
Tati was very complementary of Justin.
She said: “It was marvelous and unforgettable… He has quite a fit body and looked great naked.”
“Take it from me, he’s well endowed- and very good in bed.”
Tati claims that Justin called her the day after their night together and asked to see her again, but she declined.
She said: “I just didn’t have the strength. Justin has so much stamina.”
It is thought that she met Justin at a club in Rio which is known to be a brothel.
While Justin’s camp have yet to comment on the claims, Marcus Mion, a club owner in the area, says Tati wasn’t one of the girls Justin took back to his villa.
Marcus said: “I know all the girls who went. I personally went round asking inviting them on behalf of Justin, and I put each one in the van that took them there.
“Tati Neves wasn’t one of them. She’s also not the type of girl who frequents the club.”
Tati previously appeared on Brazilian TV show, where she wouldn’t confirm whether or not she had slept with Justin.
When asked by the interviewer if she had kissed Justin, she replied coyly: “What do you think, if I was sleeping in the bedroom, just me and him.”