Angelique Kerber has returned to top spot in the women’s world rankings, while Rafael Nadal is back in the men's top four.
Kerber ends Serena Williams’ latest stint as world number one after the pregnant American’s points for winning in Rome last year dropped off the rolling 12-month system.
Williams, 35, will not play again this season but has said she plans to return at some point in 2018.
This is Kerber's third spell in top spot and she begins her 26th week in all as number one. Williams has spent a total of 319 weeks as the world's best.
However, with Kerber having struggled to replicate her form of 2016, her position in top slot is likely to come under threat from Karolina Pliskova and Madrid Open champion Simona Halep in the coming weeks and months.
Halep rises from eighth to fourth in the latest ranking list following her success in the Spanish capital, one place behind Pliskova.
Nadal won the ATP event in Madrid to stretch his unbeaten run on clay and that victory has moved him back into the top four, above Roger Federer, who slips to fifth.
Andy Murray still heads the rankings from Novak Djokovic although the Scot’s form will need to improve in the coming months if he is to hold off the charging Nadal and Federer. The latter started the season well and after an extended break is due to return to action at the French Open later this month.
Of the other Britons in the top 100, Kyle Edmund is now 53rd, Aljaz Bedene 55th and Dan Evans 56th.
On the women’s side, Naomi Broady is back as British number two ahead of Heather Watson.
The duo are now 126th and 127th respectively with both struggling to make the main-draw cut for Wimbledon. That deadline is next Monday with the cut likely to come around 100.
