WTA Tour Finals: Serena Williams and Angelique Kerber qualify

Serena Williams and Angelique Kerber, battling it out for the world number one ranking, are the first two women to qualify for the season-ending WTA Tour Finals in Singapore, the WTA said on Monday.

World number one Williams, who leads Kerber by 190 ranking points, has won the title five times but missed last year's event through injury.

Kerber, who won her first grand slam title at the Australian Open in January and who reached the final at Wimbledon, will be making her fourth appearance in the Oct. 23-30 event, reserved for the top eight-ranked players of the year.

"I'm very proud and excited to qualify for the BNP Paribas WTA Finals in Singapore," said American Williams, who will try to break the Open-era record of 22 grand slam singles titles she shares with Steffi Graf by winning the US Open which starts next week.

"It is one of the most important events of the year and we all fight to qualify in the top eight," Germany's Kerber said in a statement released by the WTA. "I have great memories from my other experiences at the tournament and I hope to play some great matches and win the title."