Angelique Kerber cruised into the third round of the Indian Wells WTA hard court tournament on Saturday with a 6-2, 6-1 victory over fellow German Andrea Petkovic.

Second-seeded Kerber, assured of a return to the world number one ranking at tournament’s end after the injury withdrawal of Serena Williams, needed just 58 minutes to get past her good friend and Fed Cup teammate and now awaits either Pauline Parmentier of France or Yulia Putintseva of Kazakhstan.

Despite the scoreline, Kerber said it was never easy to play an opponent she knows so well.

“We’ve known each other actually forever,” Kerber said. “I was just trying to focus in on my game, play my game and be aggressive.”