HONG KONG: Top seed Angelique Kerber on Tuesday sailed through the first round of the Hong Kong Open with a straight sets 6-4, 6-4 victory over Maria Sakkari.

The reigning Australian and US Open champion beat the Greek player, ranked 97th in the world, in an hour 21 minutes.

The 28-year-old German, who is currently in the top spot in the Road to Singapore rankings, will face American Louisa Chirico in the second round.

In other first round matches, defending champion Jelena Jankovic, who beat Kerber in last year’s Hong Kong final, eased through American Samantha Crawford 6-3, 6-1 in slightly more than an hour.

Danish Caroline Wozniacki, former world number one and now fifth seed, beat China’s Zheng Saisai 6-1, 6-4 to advance to the second round.

But former US Open champion, Australia’s Samantha Stosur, crashed out in the first round in a 6-3, 6-4 defeat by Nao Hibino of Japan.

Pain forces China’s Zhang out of Tianjin Open

Asian No. 1 Zhang Shuai crashed out of the Tianjin Open on Tuesday in the latest home-turf blow to the Chinese star.

Zhang withdrew from her match against unseeded compatriot Peng Shuai, who will proceed to the second round, without hitting a ball.

“I have some pain in the waist and knee,” the Tencent Sports website quoted her as saying at a press conference in the northern port city.

“It’s the second time I’ve had to pull out of the Tianjin Open because of injury in three years, which is very disappointing,” she added.

The home soil loss is Zhang’s second in a week after she was defeated in the quarter-finals of Beijing’s China Open.

In another Tianjin upset, the US’ Shelby Rogers, ranked 66, despatched Russia’s third-seeded world number 19 Elena Vesnina 7-5, 4-6, 7-6 in a tight match.

Puerto Rico’s Monica Puig saw off Japan’s Kurumi Nara in a swift two-set victory.

Meanwhile, the USA’s Alison Riske — who won the tournament in 2014 — beat Tímea Babos of Hungary 2-6, 6-4, 6-3 to secure a second-round berth.

China has hosted an increasing number of WTA tournaments as it seeks more clout in the game.

The Tianjin Open carries a total prize purse of $426,750, according to the WTA’s website.