Jack Sock celebrated his U.S. Open win over Cilic with a fantastic fencing flourish

American Jack Sock advanced to the U.S. Open fourth round for the first time when he beat 2014 Open champion Marin Cilic 6-4, 6-3, 6-3 on Friday.

And the 26th-seeded Sock celebrated this big win in a unique way — turning his racket into a fencing blade and sparring with an invisible foil.

The fencing flourish may have been in honor of fencer Miles Chamley-Watson, New Yorker and Sock's USA teammate at the Rio Olympics. And it appears Chamley-Watson approves:

It's been quite a year for the 23-year-old Sock, who won bronze in doubles and gold in mixed doubles at the Rio Olympics. He is now 2-0 against Cilic, having come back from two sets down to win their Davis Cup match this year.

Sock will next face Jo-Wilfried Tsonga in the round of 16.

The Associated Press contributed to this report.