Jessica Pegula finished round-robin singles play at the WTA Finals with a 3-0 record a year after going 0-3 at the season-ending championship, heading to the semifinals with a 6-3, 6-2 victory over Maria Sakkari.
The fifth-seeded Pegula extended her overall winning streak to eight matches, including a title at the Korean Open last month.
The 29-year-old American has won all six sets she's played in Cancun so far and will play in the semifinals on Saturday. Sakkari, who is ranked No. 9 but got into the eight-player field when No. 8 Karolina Muchova withdrew with an injured right wrist, went 0-3 and dropped every set.
