Roger Federer equalled his best start to a season since 2006 with a 7-5, 6-1 win over Chung Hyeong to book his spot in the semi-finals of the Indian Wells Masters.
Federer, who is seeking a record sixth Indian Wells title, extended his win streak to 16 straight matches, equalling the start he had to the 2006 ATP calendar season.
Federer moves to the semis where he will face Croatian Borna Coric who outlasted seventh seeded Kevin Anderson 2-6, 6-4, 7-6.
Meanwhile, it took Daria Kasatkina just 58 minutes to dispatch former No 1 Angelique Kerber 6-0, 6-2 in their women's quarter-final in Indian Wells.
The 20-year-old Russian, who was runner-up at the WTA Dubai Duty Free Tennis Championships last month has not dropped a set in four matches at the tournament, knocking out US Open champion Sloane Stephens and No 2-ranked Caroline Wozniacki along the way.
"Maybe, yeah, from the side or with the score it looks like it was simple, but of course it's not," Kasatkina said. "I knew that in one moment if I will lose focus just for a second, they will come back and then the big battle, five hours again, will start."
The German never managed a break point against Kasatkina's serve. The Russian connected on 82 per cent of her first serves, winning 22 of 32 first-serve points.
"This one I will try to forget as fast as possible," Kerber said.
She will next go up against Venus Williams, who reached the last four at the event for the first time since 2001 as she beat Carla Suarez Navarro 6-3, 6-2.