Victoria Azarenka from Belarus (Photo: AP)
Losing to Ekaterina Makarova of Russia 1-6, 6-2, 6-3 in the second round ended Azarenka's 18-match winning streak to start the season.
Meanwhile, Rafael Nadal spoiled Benoit Paire's 24th birthday by sweeping past the Frenchman 6-3, 6-4. The fifth-ranked Nadal's hopes of returning to the top four in time for the French Open were boosted by Novak Djokovic's loss on Tuesday.
Azarenka double-faulted five times and got in just over half of her first serves. The 24th-ranked Makarova had 60 percent first-serve accuracy.
The Belarusian berated Alves after picking up a second code violation for smashing her racket in the third set.
''After all you've done, how are you still in the game?'' Azarenka shouted at the official while on court.
Azarenka said she felt confused by some refereeing decisions.
''I didn't understand what happened, what I did,'' she said. ''I was very sure that I didn't have a code violation, that's why I broke my racket.''
The third-ranked Azarenka tried to explain the loss.
''I played more against myself, trying to prove to myself certain things, more than I was focusing on my opponent,'' she said.
Azarenka, who missed Indian Wells and the Miami Open in March because of an ankle injury, said she still felt rusty. She's looking forward to another clay tournament - Rome - before heading to Roland Garros.
''I have been making mistakes,'' she said. ''But that's what comes after not playing for a long time. I still have another tournament before the French Open to compete in.''
In men's play, sixth-seeded Tomas Berdych of the Czech Republic beat Jerzy Janowicz of Poland 6-7 (3) 6-3, 6-2, and Kei Nishikori of Japan downed Viktor Troicki of Serbia 7-5, 6-2.
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