India, Sept. 2 -- Reigning US Open champion Jannik Sinner encountered a bizarre incident on Monday after cruising past No. 23 seed Alexander Bublik in the round of 16 at Arthur Ashe Stadium. The world No. 1 dominated the Kazakh 6-1, 6-1, 6-1 in just an hour and 21 minutes to book his place in the New York quarterfinals for the third time.

The awkward moment unfolded after his on-court interview, when Sinner picked up his kit bag and walked towards fans to sign autographs. While he was obliging, one spectator attempted to open his kit bag and steal from it. Security personnel immediately intervened to prevent the theft.

Clearly displeased, Sinner shook his head in disappointment before leaving the court. The incident, which was caught on...