DUBAI, United Arab Emirates -- Daniil Medvedev opened his title defense at the Dubai Championships on Tuesday by beating Alexander Shevchenko 6-3, 7-5 in his first match since losing the Australian Open final to Jannik Sinner.

The top-seeded Medvedev had withdrawn from tournaments in Doha and Rotterdam because of fatigue and a right foot problem following his loss to Sinner at Melbourne Park.

Trailing 5-3 in the second set, Medvedev won four straight games to clinch the win and move on to face either Lorenzo Sonego or Sumit Nagal.

Among other first-round matches Tuesday, fourth-seeded Karen Khachanov beat Luca Van Assche 6-2, 6-3; fifth-seeded Ugo Humbert outlasted Gael Monfils 4-6, 6-3, 6-3; and eighth-seeded Alejandro Davidovich Fokina defeated Fabian Marozsan 6-3, 4-6, 6-1.