Whose March breakthrough was the most impressive?

Kei Nishikori (defeated Roger Federer, David Ferrer in Miami)

29%

Alexandr Dolgopolov (defeated Rafael Nadal, Stanislas Wawrinka in Indian Wells, Miami)

29%

Dominika Cibulkova reaches top 10 for the first time

24%

Flavia Pennetta (defeated Li Na, Agnieszka Radwanska in Indian Wells)

18%