RIO DE JANEIRO, Feb. 18 (Xinhua) -- Top seed Francisco Cerundolo retired from the Rio Open on Wednesday due to a lower back injury, ending his bid for a maiden ATP 500 title.
The world No. 19 was trailing fellow Argentine Thiago Agustin Tirante 6-2, 3-1 in their last-16 match at the Jockey Club Brasileiro when he stopped play to receive treatment from a physiotherapist before deciding he could not continue.
An official medical report was not immediately available.
"It's not good to win like this, especially with Fran, one of my friends," Tirante said. "I knew that he was very tired from last week, so I had to improve myself on the court and focus on me."
Tirante will meet either Francesco Passaro or Alejandro Tabilo in the next round.
Cerundolo arrived in Rio in strong form after winning last week's Argentina Open without dropping a set, and he had beaten compatriot Mariano Navone 6-3, 6-4 in the opening round on Tuesday.
His withdrawal opens up the draw for Brazilian favorite and third seed Joao Fonseca, the world No. 38, who will face Peru's Ignacio Buse in the round of 16 on Thursday as he looks to recover from a slow start to the season in front of his home crowd.
Second seed Luciano Darderi of Italy and Argentine fourth seed Sebastian Baez were eliminated in the first round on Tuesday. Darderi lost to Juan Manuel Cerundolo while defending champion Baez fell to Portugal's Jaime Faria. ■
