A maxidress-clad Blake took a day out from filming the new Gossip Girl season five to cheer on Serena Williams, grinning with delight when Williams made her way into the quarter finals.
Mamma Mia star Amanda Seyfried also enjoyed at day out at the championships match, held at Flushing Meadows, New York, as she posed for photos in the hospitality area. The actress swapped her red carpet frocks for a pared-down tee and denim cut-offs.
Other celebs in attendance included High School Musical star Vanessa Hudgens and singer Ciara.
By Annabelle Spranklen