No. 13 John Isner walks off the court after losing to Philipp Kohlschreiber of Germany. It was his third straight loss in the third round at the U.S. Open. (AP Photo/Elise Amendola) (Elise Amendola/AP)

John Isner, the highest ranked American in the men’s field, was eliminated Saturday in the third round for the third straight year — each time to German Philipp Kohlschreiber. This latest loss may have been the most painful — Isner dropped three tiebreakers in the match, losing 7-6 (7-4), 4-6, 7-6 (7-2), 7-6 (7-4).

Isner, the No. 13 seed, said before the match that meeting the same opponent at the same event in the same round for three years in a row was “bizarre.”

Afterward, he was simply disappointed.

“I never expected I could see him again this year in that round,” Isner said. “I really don’t think that had anything to do with it. . . . It’s super disappointing that I’ve lost to him three times in a row at this tournament. I have the crowd on my side, I have a lot of things going my way as far as that goes, I wasn’t able to pull through three times in a row, it’s a bit annoying.

“He was just better three times in a row here. I’ve got to be better. I know I can be, just not showing it.”

Isner had 42 aces, but struggled to capitalize on his break chances, winning only one of 12 against Kohlschreiber, the No. 22 seed.

Isner’s loss and Sam Querrey’s loss to top seed Novak Djokovic have eliminated all the American men in the singles field before the fourth round.

“It’s disappointing for me personally, not for America as a whole,” Isner said. “For me personally it’s very disappointing because I should hold myself to a pretty high standard. . . . America as a whole, that’s not for me to worry about.”

Wimbledon champ ousted

Another top women’s player fell in the first week of the U.S. Open, this time Wimbledon champion and No. 3 seed Petra Kvitova to Aleksandra Krunic, 6-4, 6-4.

Top seed Serena Williams, who won her match on Saturday against Varvara Lepchenko, 6-3, 6-3, and No. 5 seed Maria Sharapova are the top women’s players left after No. 2 seed Simona Halep lost on Friday and No. 4 seed Agnieszka Radwanska lost in the second round. No. 6 seed Angelique Kerber also lost on Friday to 17-year-old Belinda Bencic.

“I wanted to win today, and unfortunately I didn’t,” Kvitova said. “I think she played really unbelievable tennis, and she put a lot of balls back, almost all of them.”

Krunic, who beat American Madison Keys in the second round, started strong in the match, breaking Kvitova in her first service game. With the second set tied at four games, Krunic broke Kvitova and then held serve in the next game to win the match.

Krunic, who made the tournament via a qualifier into the tournament, said she wasn’t expecting to advance to the fourth round.

“I don’t have anya pressure from the beginning since I step on the court,” Krunic said. “When I don’t put the extra pressure on myself, it’s just much easier for me not to think about the crowd and anyone. I was trying to take the positive things from the crowd. I didn’t expect that so many people would cheer for me.” . . .

Raonic wins tiebreaker duel

Milos Raonic and Victor Estrella Burgos played to a tiebreaker in all three of their sets in their third-round match, but it was Raonic who excelled, winning 7-6 (7-5), 7-6 (7-5), 7-6 (7-3).

“It is a coin toss in a lot of ways,” Raonic said of tiebreakers. “It can go both ways, but with my serve and ability to finish points quickly and the kind of pressure that puts on my opponents, I can maybe shift odds in my favor. When things aren’t necessarily going well throughout the set, I feel like, okay, focus on makingsure this goes all the way through. Take care of your serve and give yourself a shot in the breaker.”

Raonic, who won the Citi Open in Washington earlier this month, congratulated Estrella Burgos on his showing after the match. At 34, Estrella Burgos is the oldest player to make his main-draw debut here. He’s played mostly Challengers, but said he will play more ATP tournaments.

“For me, was the best week,” Estrella Burgos said. “I think third round here in the U.S, Open, today I have a very good match. I think I lost today, but today was my best match. I played very good level. The three sets were very close. I was serving for the set in the third set. I cannot close the set, but I’m not too sad, because I have a very good week.”