The U.S. Open Tennis Championships begin today. Serena Williams, who opens her quest for a third successive US Open title with a meeting against fellow African American Taylor Townsend tomorrow, said Arthur Ashe would have been proud. On Arthur Ashe Kids' Day that drew legions of young hopefuls to the National Tennis Center on Saturday, Williams pondered the significance of her clash against the 18-year-old Townsend and the legacy of Ashe, whose name graces the center court stadium.Williams said she took a lot from the example set by Ashe, a three-times major winner who claimed the US title in 1968, and died in 1993 from AIDS-related pneumonia. The top seed said playing Townsend would be special and it was going to be a great match for her.