Novak Djokovic slams own ‘awful’ serve after US Open walkover against Djere

• Champion leads 6-4, 6-4, 2-0 when fellow Serb retires
• Women's No 3 seed Gauff beats Tatjana Maria 6-4, 6-0

Novak Djokovic took another step toward a record 25th grand slam singles title and a rare US Open repeat when fellow Serb Laslo Djere retired with an injury during the third set of their second-round encounter on Wednesday night beneath the roof of Arthur Ashe Stadium.

Three days short of a year after fighting back from two sets down against the same opponent at the same stage in the same venue, the second-seeded Djokovic saw to it that lightning didn't strike twice, even as a sudden thunderstorm suspended play across the grounds and created sweat-box conditions inside the main show court. Wearing a sleeve over his surgically repaired right knee, the world No 2 led 6-4, 6-4, 2-0 when Djere signalled he could no longer continue, a welcome tap out from an opponent who had pushed him the distance in each of their previous two meetings.