Move over, Karlie and Taylor, there’s a new bestie duo in town. Serena Williams covers the April edition of Vogue and talks about her friendship with tennis champion and professional rival Caroline Wozniacki. Williams, who’s still the number one-ranked female player in the world, tells writer Rebecca Johnson what connects them. “It’s hard and lonely at the top,” she says. “That’s why it’s so fun to have Caroline and my sister, too. You’re a target when you’re number one. Everyone wants to beat you. Everyone talks behind your back, and you get a lot more criticism. God forbid I lose. It’s like ‘Why?’ Well, I am human.” The on-court rivals vacation together, but have never played a match just for fun. “I play tennis all year,” Wozniacki says. “On my vacation, I did not want to hit.” Both ladies were shot by Annie Leibovitz, with Williams wearing a Rag & Bone sheath dress for the cover and a Tate diamond bracelet. Vogue is also looking to attract some younger readers with the coverline: “L.A. Stories. Hanging Out With Kendall, Gigi, Ansel, and Justin.” No last names necessary. UPDATE: Vogue has put a Gallery online of (what they are calling) “Hollywood’s New Brat Pack’ View the Mario Testino shots HERE.