It’s been a big two weeks for Serena Williams – last week she was voted WTA Player Of The Year for the seventh time, and earlier this week she was named Sports Illustrated’s Sportsperson Of The Year.

And now, the World No.1 has achieved another milestone – a more social kind of milestone.

She’s become the first women’s tennis player ever to surpass 6 million followers on Twitter.

Here are the Top 5 most-followed WTA players on Twitter as of the time of publishing:

1. Serena Williams (6.00M)
2. Sania Mirza (3.24M)
3. Maria Sharapova (1.91M)
4. Venus Williams (1.35M)
5. Caroline Wozniacki (0.98M)

Additionally, Williams is the second-most-followed professional tennis player on Twitter, male or female, with only one ATP World Tour player passing 5 million (Rafael Nadal has 8.80M followers).

And here’s another look at her big SI cover story from Monday – she crossed 6 million that night:

The 2015 #SISportsperson of the year is… @serenawilliams! https://t.co/Zt4QEIl1MY pic.twitter.com/MBVZpWgQiV

— Sports Illustrated (@SInow) December 14, 2015