After Kristina Mladenovic pulled off a stirring tweener to reach her first Grand Slam quarterfinal at the US Open this season, she said she often practices the shot.
Practice makes perfect.
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Check out Mladenovic pull off this tremendous tweener in practice.
Look a little familiar?
Here's Mladenovic's stunning tweener from her US Open upset of Ekaterina Makarova.
Photo credit: Christopher Levy