Alexander Zverev was somewhat critical of his Rio Open performance despite securing victory.
The German continued the South America clay court swing following an early exit at the Argentina Open courtesy of Francisco Cerundolo.
Once again the top seed, the 27-year-old is keen for a stronger performance in Brazil, and he has made a winning start.
But despite securing a victory, Zverev was not happy with the way he played and expects better from himself as the tournament progresses.

What did Alexander Zverev not like about his performance to start the Rio Open?
Alexander Zverev took on Yunchaokete Bu in his first match at the Rio Open in his career.
The German made a slow start as he saved a set point on his opponent’s serve before claiming set one via a tiebreak.
Zverev, who won just 71% of the points behind his first serve, opened up a 4-1 lead in the second set.
However, Bu found a way back and levelled the set at 4-4, before Zverev played the final two games to wrap up a 7-6, 6-4 win.
Post-match, the World number two made it clear that he was not satisfied with what he produced on court. “Not a great match by me but he played some good tennis,” he said.
“He made it difficult for me. Actually it’s surprising because you know I actually played really really well in practice here the whole week, so I hope it’s just the first match.”

Who will Alexander Zverev play in his next match?
Zverev has booked a spot in round of 16 at the Rio Open where he will face Alexander Shevchenko.
Wednesday’s encounter will mark the first time that the pair will play against each other on the ATP Tour.
Shevchenko has won just three of the eight matches he has played so far this season, and they came in the United Cup and Davis Cup.
His 6-4, 6-2 victory over Felipe Meligeni Alves at the Rio Open was a confidence booster for a player preparing for one of the toughest tests of his career so far.
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