Robson out injured, huge win for Keothavong
Britain's Laura Robson went out of the Pattaya Open in Thailand after retiring injured during her first round match.
Robson was trailing Uzbekistan's Akgul Amanmuradova 5-2 in the opening set when she was forced to pull out.
The 18-year-old - ranked 118th in the world - was beleaguered by injury towards the end of last year, and played in the Australian Open less than a month after coming off crutches following a shin stress fracture. She came through three qualifying matches to make the first round in Melbourne, but lost to former world number one Jelena Jankovic in her opening match. She also played a part in Britain's successful Fed Cup match against Israel last week.
Heather Watson also went out of the Pattaya Open in the first round, losing 6-4 6-2 to America's world number 59 Vania King.
Keothavong broke her opponent five times during the match, and successfully saved five of the six break points the Slovakian held against her as she picked up the biggest scalp of her career.
"I didn't have too many expectations going in to today's match as I felt a little under-cooked having only arrived yesterday from Fed Cup in Israel but I surprised myself," Keothavong said.
"The courts are super fast here and it's hot and humid. Cibulkova only arrived yesterday too but I think the courts favoured my game more and I was quicker to adjust."
Top seed Vera Zvonareva came through her opening match comfortably, beating local qualifier Varatchaya Wongteanchai 6-2 7-5, while third seed Daniela Hantuchova also made the second round with a 6-2 6-0 thrashing of wildcard Nungnadda Wannasuk.