Following surgery on his right elbow in October, the Japanese player had to postpone his comeback last month after he was forced to pull out of the Cincinnati Masters and U.S. Open after testing positive for COVID-19.
Nishikori's previous match was a third-round loss to Alex de Minaur at the 2019 U.S. Open. He jumped out to a 5-0 lead over Kecmanovic and later led 6-4, 4-4, but won only two of the next 10 games. The 47th-ranked Kecmanovic has been a long-term regular training partner of Nishikori's.
“It means a lot to me to win this match," the Serbian said. "I have been playing with him since I was 13, so this is very special.” Also, fifth-seeded Hubert Hurkacz defeated Joao Sousa 6-3, 7-5; Guido Pella beat Yoshihito Nishioka 6-3, 6-0; and Austrian wild-card entry Sebastian Ofner rallied to beat Radu Albot 6-7 (5), 6-4, 7-6 (4).
Fabio Fognini is the top-seeded player at the clay-court event, which was rescheduled from July and is the first European tournament on the ATP Tour since February in Marseille.
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