SHANGHAI (AP) – Roger Federer had to overcome a second-set stutter. Juan Martin del Potro and Alexander Zverev had to overcome illness.
All three still advanced at the Shanghai Masters on Wednesday.
Federer, the defending champion, beat Daniil Medvedev, 6-4, 4-6, 6-4, in the second round despite being broken late in the second set.
The third-seeded del Potro trailed in the first set and in the tiebreaker but rebounded both times to beat Richard Gasquet 7-5, 7-6 (7).
The fourth-seeded Zverev was also struggling with a cold, but he beat Nicoloz Basilashvili, 7-5, 6-4.
Basilashvili arrived in Shanghai after beating del Potro in Beijing to win his second career title.
Zverev is playing in Shanghai without his coach, Ivan Lendl, who was in Beijing last week. Lendl flew back to the United States to have wrist surgery, which Zverev said was caused by playing too much golf. Lendl is due to return to the tour before the end of the season.
Earlier, 10th-seeded Stefanos Tsitsipas beat Karen Khachanov, 6-4, 7-6 (8) – the second straight year that the Greek player has defeated Khachanov in the second round in Shanghai.
“We played here last year and it was the place I got my first ATP win,” Tsitsipas said. “I knew today was going to be a different match. I played every single point as if there was no tomorrow.”
