Williams prevailed versus Tsvetana Pironkova on Wednesday, advancing to a semifinal versus Victoria Azarenka, a rival and a friend. A championship would tie Williams with Margaret Court at 24 major singles titles. Down a set and a break to the unseeded Tsvetana Pironkova in the quarterfinals of the United States Open, Serena Williams was in danger of succumbing to a story line even better than her own. Pironkova is not only unseeded. She is unranked and was playing in her first tour event in more than three years. Not even Williams, a 38-year-old master of the comeback, has taken it […]