Angelique Kerber is back at No. 1, replacing Serena Williams atop the WTA rankings.

Monday's move up from No. 2 represents Kerber's third stay to the top spot, for a total of 26 weeks.

Because of a quirk in the rankings due to a slight shift in the tour calendar, Williams briefly returned to No. 1 last month, even though she has not played a match since winning the Australian Open in January. It was her 23rd Grand Slam title.

Williams revealed last month that she is pregnant.

She is due to give birth in the fall and is taking the rest of the year off, but she plans to return to competition in 2018.

_

More AP tennis coverage: https://apnews.com/tag/apf-Tennis