Cameron Diaz and Ashlee Simpson Hugging at the US Open!

Cameron Diaz and Ashley Simpson hugging

Tennis fans, Cameron Diaz and Ashlee Simpson looked like they were the best friends at the US Open.

The two stars were seen hugging courtside after watching Swiss tennis star Roger Federer beat 13th-seeded Jurgen Melzer of Austria.
25-year-old Ashlee attended the match with her husband, singer Peter Wentz. Cameron, on the other hand, came with a female friend who she chatted to throughout the game.
Other celebs who attended the game at the USTA National Tennis Centre in Flushing Meadows, New York, included Gwen Stefani with husband Gavin Rossdale and 'Sopranos' actor Steve Schirripa.
No. 2 Federer will next play No. 5 Robin Soderling of Sweden who ended Federer's streak of 23 consecutive Grand Slam semifinals by beating him in this year's French Open quarterfinals.