New Delhi, Aug. 6 -- Alexander Zverev's campaign at the National Bank Open in Montreal ended after the World No 3 lost 7-6, 2-6, 4-6 to Tallon Griekspoor in the second round on Wednesday.

The defeat marked Griekspoor's third career victory over a top-five opponent and sent the Dutchman into the third round of the ATP Masters 1000 tournament.

Zverev entered the tournament as the No 1 seed after several leading players, including world No 1 Jannik Sinner and Novak Djokovic, withdrew from the event.

As one of the top 32 seeds, the German received a first-round bye and opened his campaign directly in the second round against Griekspoor, who had already played and won his opening match.

The opening set was closely contested, with neither p...