Haase dumped out in Sao Paolo
Fifth seed Robin Haase exited the Brazil Open in the first round after suffering a straight sets defeat to Joao Souza.
The Dutchman never got going against his wildcard opponent and the home fans were given something to cheer as the Brazilian claimed a 7-5 6-4 victory.
Another seed also had a day to forget as Leonardo Mayer was beaten in a gruelling contest by fellow Argentinian Guido Pella.
All three sets went to a tie break and it was Pella who showed the greater stamina as he beat the seventh seed 7-6 (7/4) 6-7 (7/3) 7-6 (7/4).
Horacio Zeballos emerged victorious in the other first round clash, but only after battling for more than two hours to see off Pablo Cuevas 7-6 (7/3) 3-6 6-3.
In the women's tournament, top seed Carla Suarez Navarro advanced without drama but number four Francesca Schiavone suffered an early exit.
Navarro was a 6-2 6-2 winner over Timea Babos, but Shiavone lost 6-4 1-6 7-5 to Barbora Zahlavova Strycova.
The other seeds in action all came through unscathed as fifth seed Monica Niculescu beat Anna Schmiedlova 6-0 4-6 6-2 and number six Alexandra Cadantu saw off wild card Gabriela Ce 6-1 6-3.
Number eight Paula Ormaechea defeated wild card Beatriz Haddad Maia 6-1 6-2.
Also in first-round action, Chanelle Scheepers was a 4-6 6-0 6-3 winner over Julia Glushko while Yaroslava Shvedova battled past Silvia Soler-Espinosa 7-6 (7/1) 7-6 (7/1).