One Love: U.S. Open Couples!

From Chelsea Clinton & Mark Mezvinsky's PDA to Gwen Stefani & Gavin Rossdale's cheer section, see which star pairs are Grand Slam fans!

GWEN & GAVIN

Tennis superstar Roger Federer was showing his all-court finesse under the lights at Arthur Ashe Stadium, but all eyes were on his good pals Gwen Stefani and Gavin Rossdale, whose famous faces were broadcast on the Jumbotron during the Sept. 6 match.