Kerber — oldest to debut at World No.1

Facts on Angelique Kerber becoming the new world number one after Serena Williams lost top spot Friday after a run of 186 weeks when she was beaten by Karolina Pliskova in the US Open semifinals:

- Kerber becomes only the second German woman to achieve the world's top ranking since computer rankings were introduced in 1975, and the first since Steffi Graf spent the last of her record 377 weeks at No.1 in March 1997.

- At 28, she is the oldest player to make her debut at No.1, a record previously held by Jennifer Capriati, who was 25 years, 200 days when she reached No.1 in October 2001.

- Kerber’s rise to world No.1 brings to an end the reign of Serena Williams, whose sixth stint in the top spot began more than three years ago, on February 18, 2013.

- At 186 consecutive weeks, the American’s most recent stay at No.1 ties the Open Era record for most consecutive weeks at No.1 held by Graf. This is the 88th time the No.1 ranking has changed hands over the past four decades.

- Kerber has enjoyed a breakout year. She defeated Williams to win her maiden Grand Slam title at the Australian Open, and followed up by advancing to the Wimbledon final and capturing a silver medal in singles at the Olympics.

- Going into the US Open semifinals Friday, Kerber led the WTA for most main draw match wins this season, at 52-14.