Japan's Naomi Osaka remains top of the latest women's world tennis rankings released by the WTA yesterday as the build-up to Wimbledon continues. Osaka has a best 6,377 points to narrowly lead Australian Ash Bartey who trails on 6,125. Both the top two and third-placed Karolina Pliskova are in action at the WTA event in Birmingham, England, this week as they prepare for the grass grand slam at Wimbledon from July 1. German number six Angelique Kerber meanwhile will play in Majorca.