Tyson Beckford -- Playing With His Grown Man Toy Again

Tyson Beckford and ex-girlfriend Shanina Shaik reunited at the U.S. Open this week, a month after her brief dalliance with Justin Bieber ... that led to Beckford giving us one of the greatest quotes ever.

As you'll recall ... Bieber and Shaik were photographed together in July hanging out on a yacht in Ibiza and when we asked Tyson about it last week ... he absolutely DESTROYED Biebs with an epic one-liner.

Game, set, match.