Question: What is the name of this retired professional tennis player and former World No. 1 who was the defending champion of the 2004 Siebel Open - Singles?
Sentence (from "Lucie Šafářová"): She also won the 2015 Australian Open, 2015 French Open, 2016 US Open, 2017 Australian Open and 2017 French Open women's doubles titles partnering with Bethanie Mattek-Sands.
Relevant evidence: No