Wimbledon champion Garbine Muguruza officially became the world number one as the Women's Tennis Association (WTA) updated the rankings on Monday.
Muguruza becomes the 24th woman overall to hold the number one ranking and the second player representing Spain to achieve this historic milestone since computer rankings were introduced in 1975.
Muguruza joined US Open champion Rafael Nadal in making Spain the first country since the United States 14 years ago to top the WTA and ATP rankings. Andre Agassi and Serena Williams were both No 1 in 2003.
The 23-year-old takes over from Karolina Pliskova at the top of the rankings, after the Czech's quarter-final defeat in the US Open by Coco Vandeweghe.
"Becoming the WTA No 1 in the world is a dream come true," the WTA website quoted the Spaniard as saying.
"And I am very proud to share such a special moment for our country with Rafael Nadal, the best role model I could ever have. I look forward to continue working hard to keep this position," she added.