Top seed Kei Nishikori has been knocked out of the opening round of the Rio Open, following a straight sets defeat at the hands of Thomaz Bellucci of Brazil.
The Japanese world No. 5, who had suffered a humiliating loss against unseeded Ukrainian Alexandr Dolgopolov in the Argentina Open final two days ago, was broken in the first game before he went on to lose 6-4, 6-3 in just 79 minutes. Up next for Bellucci is a battle with compatriot Thiago Monteiro.