Jean Catuffe/Getty Images(NEW YORK) -- After an incredible run at the U.S. Open, Serena Williams' professional career most likely ended Friday after losing to #46 Ajla Tomljanovic who defeated her 7-5, 6-7(4), 6-1. The 23 time champion took a professional bow on the same court she won her first grand slam tournament in 1999 and from