Due to a shift in the 2017 WTA calendar, Serena Williams returns to WTA World No.1 today, April 24 for her 317th week on top of the WTA rankings.
In 2016, the Porsche Tennis Grand Prix – Stuttgart was held a week earlier than this year’s event, resulting in last year’s ranking points to drop a week sooner.
Angelique Kerber, two-time defending Stuttgart champion, can reclaim the top spot by advancing to the semifinals this week. As top seed, Kerber will receive a first-round bye, and will need to win two matches in order to return to WTA World No.1.