Genie Bouchard might've left the U.S. Open in defeat -- but she's definitely winning back home at the beach with none other than Hannah Davis' hunky big brother.
The Canadian tennis star -- who got knocked out of the U.S. Open in the first round a couple weeks ago -- was seen cuddling up with Conn Davis Jr. Sunday in Miami. He's directly related to the model ... who's now married to Derek Jeter. Worlds are colliding!!!
Not only did Genie and Conn get close on shore, but they were also pretty affectionate as they made their way into the water .