PARIS -- Jack Sock, the No. 14 seed, ranted and railed as he lost in the first round of the French Open for a second consecutive year on Tuesday.
His tormentor Tuesday was 136th-ranked Jurgen Zopp of Estonia, who won 6-7(4), 6-2, 4-6, 7-6(5), 6-3.
Sock blamed the Brazilian umpire, disputing her calls and questioning her competence.
"This is your job, right?" Sock asked after serving a double fault to go 5-2 down in the second set. "Hard to believe."
On his way to losing the fourth set, he said to the umpire during a changeover: "You're atrocious. If we could request a new one, I would. This is shocking stuff. Can I request a new ref?"
Sock's best showing at Roland Garros was in 2015, when he reached the fourth round.