Karolina Pliskova of the Czech republic advanced to the Bank of the West Classic semifinals Friday, beating Croatia's Ajla Tomljanovic 6-2, 6-4.
The 11th-ranked Pliskova will make her debut in the top 10 when the new rankings are released Monday.
Only world No. 1 Serena Williams, who withdrew from Stanford with an elbow injury, has more wins (40-1) than Pliskova (38-14) this year and the fourth-seeded Czech player snapped a tie with Williams for most aces on the tour. Pliskova has 361 to Serena's 352.
On Saturday, Pliskova will meet the winner of a later match between No. 60 Varvara Lepchenko of the United States and No. 63 Mona Barthel of Germany.
Pliskova will become the eighth Czech woman to be ranked in the top 10 since the current system was introduced in 1975, and three Czech women will be among the top 10 for the first time in WTA history.