Johanna Konta reaches Shenzen Open semi-finals but Kerber loses in Brisbane
British number one Johanna Konta continued her good start to 2017 by reaching the semi-finals of the Shenzhen Open in China.
The world number 10 defeated Kristyna Pliskova of the Czech Republic, ranked 60th, 6-4 6-7 (11-13) 6-3.
Her next opponent will be another Czech, Katerina Siniakova, who beat Serbian Nina Stojanovic 6-3 6-4.
Konta is now the highest-ranked player left in the event after world number three Agnieszka Radwanska's exit.
The Polish top seed was beaten 6-2 3-6 6-0 by American world number 39 Alison Riske, who will face Camila Giorgi of Italy in the last four.
Konta looked in control early on against her opponent - the twin sister of world number six Karolina Pliskova - as she took the first set with a single break of serve.
Neither player could force a break point in the second set and in the resulting tie-break Konta wasted two match points before the big-serving Pliskova levelled the match on her fifth set point.
But Konta stayed firm in the final set, claiming the break and reaching the semi-final on her fifth match point.
"I am very happy to have extended my stay here," she said.
"She is one of the best servers on tour so I knew I was going to have a hard time on her service games. I was very happy I was able to get that break in the third and see it out in the end."
World number one loses in Brisbane
Top seed Angelique Kerber lost 6-4 3-6 6-3 to Ukraine's Elina Svitolina in the quarter-finals of the Brisbane International.
The world number one looked to have turned things around after losing the first set but Svitolina, the world number 14, hit back to win the decider.
Kerber said she was not worried about how the early loss would affect the defence of her Australian Open crown in Melbourne later this month.
"I think Grand Slams are always completely different," she said. "It doesn't matter how you play before."
WTA Finals champion Dominika Cibulkova, the second seed, also went out, going down 6-3 7-5 to France's Alize Cornet.
French Open champion Garbine Muguruza did reach the last four, beating Svetlana Kuznetsova 7-5 6-4, and third seed Karolina Pliskova was a 3-6 6-2 6-2 winner over Roberta Vinci.
Meanwhile, Germany's Julia Goerges staged a brilliant fightback to defeat third seed Caroline Wozniacki 1-6 6-3 6-4 in the ASB Classic quarter-finals in Auckland.