In this Sept. 3, 2007 file photo, Roger Federer, of Switzerland serves to Feliciano Lopez, of Spain, during their match at the US Open tennis tournament in New York. Total prize money at the U.S. Open will top $20 million for the first time this year, with the men's and women's singles champions each earning a tournament-record $1.5 million, the U.S. Tennis Association announced Tuesday July 8, 2008.