British number one Johanna Konta beat her compatriot Heather Watson 6-4 6-4 to reach the third round of the BNP Paribas Open at Indian Wells.
Konta, ranked 11th to Watson's 108th, struggled for rhythm in the first set but dominated the second to lead 5-1.
British number two Watson, who served nine double faults, fought back but 25-year-old Konta finally came through.
Konta, who had a first-round bye, goes on to face Caroline Garcia or Evgeniya Rodina in round three in California.
It was the first meeting on the WTA Tour between Britain's two leading women.