The huge server was ranked first among her WTA tour mates for eight weeks during the summer of 2017, but spent much longer around the top 10.
The 32-year-old has had mixed success this year with a WTA 250 title in Romania in February coming amidst a relative lack of form.
Serena didn’t like players which are playing fast and serving well, so I felt like she was struggling a little bit with my game,” she said.
“Even the matches which I lost to her, I felt like it was even, you know, she would never kind of guilt me like she did some players.
Then once of course like I beat her, I always had the belief that, okay, I can beat her. To play against Iga Swiatek is much harder because she doesn’t give you anything.
With Serena, in the end her game was much more aggressive or like [Maria] Sharapova who I played. But they would at least give you light points or make some mistakes.
