Grigor Dimitrov, 78th-ranked, delivered a stunning upset of Roger Federer in the US Open quarter-finals, fighting back for a 3-6, 6-4, 3-6, 6-4, 6-2 triumph over the Swiss star who had beaten him in all seven of their prior meetings.

Grigor Dimitrov, of Bulgaria (R) shakes hands with Roger Federer, of Switzerland, aftera a US Open quarterfinal on September 3, 2019 in New York.
Grigor Dimitrov, of Bulgaria (R) shakes hands with Roger Federer, of Switzerland, aftera a US Open quarterfinal on September 3, 2019 in New York. (AP)

Fresh from a heart-breaking loss at the All-England Tennis Club, the abrupt end to Roger Federer's US Open on Tuesday raised questions whether the 38-year-old can deliver on a record-extending 21st Grand Slam title.

Federer had hoped to shake off the agony of his most recent Wimbledon final, where the top prize slipped through his fingers and into the arms of frequent rival Novak Djokovic after he failed to convert two championship points.

But unseeded Grigor Dimitrov thwarted the effort in Flushing Meadows in a five-set marathon, leaving a puzzled crowd to wonder if the Swiss will ever again hoist a Grand Slam trophy.

The 78th-ranked Bulgarian fought back for a 3-6, 6-4, 3-6, 6-4, 6-2 triumph over the Swiss star who had beaten him in all seven of their prior meetings.

"I wasn't even focusing on Roger. I was focusing on myself," Dimitrov said. "I was kind of looking at my dashboard to see where I was at really," Dimitrov added.

He will face Russian fifth seed Daniil Medvedev on Friday for a berth in Sunday's final.

Another Grand Slam for Federer?

"I don't have the crystal ball. Do you?" quipped Federer, after a reporter asked if he expected to win another Grand Slam title at his age.

"We never know. I hope so, of course. I think still it's been a positive season. Disappointing now, but I'll get back up, I'll be all right."

Federer left the court for a private medical timeout to treat his upper back near his neck before the final set but refused to blame his injury as the reason for his exit.

"I felt it the whole time. I was able to play with it. My bad not to win," the third seed said.

"This is Grigor's moment and not my body's moment, so it's OK.

"It's how it goes. I tried my best. By far not too bad to give up or anything. Grigor was able to put me away. I fought with what I had."

He batted down suggestions that his Wimbledon performance this year played a role in his surprise US Open upset.

"I didn't think of it. If you move on, it's a thing of the past. I do remember playing good semis there, so it wasn't bad. If I think of that, I'm, like, really happy," he said.

For Federer, nothing is out of the question – and not without precedent. The oldest man to win the US Open title was Bill Larned, who was 38 years, 8 months and 3 days old when he triumphed.

Of course, that was in 1911.

And past precedent is likely little comfort for Federer, who laid out for reporters an aggressive schedule of future competition.

"Laver Cup, Shanghai, Basel, maybe Paris, London. That's the schedule for now. I don't know if the team have other ideas or not," said Federer. "I'm happy to get a bit of a break now, go back to practice, reassess and attack from there."

In four months, he'll renew his effort to add to his Grand Slam coffers at the Australian Open, where he collected his last title in 2018.

"(I have) got to take the losses. They're part of the game," said Federer. 

"Looking forward to family time and all that stuff, so... Life's all right." 

Source: TRTWorld and agencies