Tuesday's Curitiba round of 32 pits Gustavo Heide against Hernan Casanova on clay. Gustavo Heide has won 6 of the last 10. Hernan Casanova is searching for form, having lost 3 in a row (6 of the last 10).

The serve is where this match separates: Heide has been winning 71.3% of first-serve points to Casanova's 61.4%, and on clay that gap compounds fast. The edge belongs to Heide — real, but not the kind you take for granted at this level.