Although she has spoken about her habit in the past, the Slovakian revealed that she had a favourite ball to sniff -- the Wilson US Open.

"It was something I was doing since I was little girl," she told reporters after her three-set victory against Russia's Anastasia Pavlyuchenkova.

The 27-year-old won in three sets, 7-5, 2-6, 6-2

"It became some kind of a habit, a ritual I do," she smilingly added.

"There is nothing more about it, it's just part of me, part of my game, part of what I do on the court."

Asked if the balls smelled good, she replied: "Wilson is fine. Wilson US Open is a good one."