“Generally I thought it was a pretty good match,” the German assessed. “It’s not easy conditions here; it’s hot, humid. You do go to your limits at times physically. I thought he played a great match. I’m definitely happy with the win and the improve …. I was physically struggling at 4-1; I really was struggling to breathe. The air is very heavy here; it’s very, very humid. I’m obviously happy that I didn’t have to play a third set.”

Next up for Zverev is Argentina’s Francisco Comesana, who outlasted Nicolas Jarry 7-6 (4), 6-7 (1), 7-6 (6).

“For sure I will do some homework,” Zverev said. “He’s a young and up-and-coming player. He’s very good; especially on this surface I think he can do a lot of damage. I’m looking forward to our first meeting.”

The world No 2’s week began with 7-6 (4), 6-4 victory over Bu Yunchaokete. Prior to Wednesday’s result, Shevchenko knocked off Brazilian wild card Felipe Meligeni Alves 6-4, 6-2.

Rio de Janeiro ATP 500, other second-round results:

• Alexandre Muller vs. Tomas Martin Etcheverry
• Francisco Cerundolo vs. Luciano Darderi
• Camilo Ugo Carabelli vs. Damir Dzumhur
• Jaume Munar vs. Jaime Faria
• Thiago Monteiro vs. Chun-Hsin Tseng
• Sebastian Baez (5) beat Mariano Navone: 6-4, 1-6, 6-3
• Francisco Comesana beat Nicolas Jarry (6): 7-6 (4), 6-7 (1), 7-6 (6)