Santa Barbara’s Kayla Day made her professional tennis world tour debut at the Australian Open and dropped a 6-2, 6-3 first-round match against Germany’s Andrea Petkovic.

Day, 17, turned professional last year after winning the U.S. Open Junior singles title. Petkovic, 29, is a nine-year veteran who has six career tournament titles on the WTA Tour. She is ranked 56th in the world.