Wozniacki, Kerber off to fast start at Wuhan Open

Angelique Kerber was in fine form against Madison Keys, before an injury forced the American to retire AFP/NICOLAS ASFOURI

Australian Open champion Wozniacki, who received a first-round bye, was barely troubled by the 61st-ranked Swede Rebecca Peterson, winning 6-4, 6-1 to set up a third-round clash with Olympic champion Monica Puig, who romped past Aliaksandra Sasnovich 6-2, 6-2.

Peterson offered some resistance in the first set, breaking Wozniacki's serve at 5-2, but faded as the Dane - who lost her first match at Japan's Pan Pacific Open last week - quickly regained control as she looks for a good run in Wuhan to secure a return to the WTA Finals, which she won last year.

World number three Kerber has already qualified for next month's Finals which will be held in Singapore and advanced after a knee injury forced her American opponent Madison Keys to retire.

The German looked set for a big win over the 2017 US Open semi-finalist and was leading 6-0, 4-1 when Keys could not continue.

Kerber, who could return to world number one with a successful end to the season, said earlier this week she was not concerned about rankings.

"For me it's the most important thing, that I go on court, play my best, have fun out there, enjoying every single moment," Kerber said Monday.

"We will see what's happening at the end of the year."

Current number one and French Open champion Simona Halep plays later on Tuesday against Dominika Cibulkova.

Nine of the world's top 10 are at China's $2.7 million Wuhan Open. US Open winner Naomi Osaka withdrew with an illness after losing the Pan Pacific Open final on Sunday.

Six spots at the WTA Finals in Singapore next month remain up for grabs with only Halep and Kerber securing their places so far.

Sixth-ranked Elina Svitolina became the biggest Wuhan casualty so far when the Ukrainian was beaten 6-4, 2-6, 6-1 by Belarussia's 20th-ranked Aryna Sabalenka.