US Open 2019: Roger Federer's 5 most painful defeats at Flushing Meadows

Roger Federer endured his 14th defeat at Flushing Meadows, and his fourth from two sets to one up, as the Swiss maestro exited the 2019 US Open at the quarterfinal stage, losing for the first time in eight matches to Grigor Dimitrov.

Following his nemesis Novak Djokovic's exit in the fourth round, the opportunity was ripe for Federer to go all the way for a record sixth time at the US Open but Dimitrov had other ideas.

The defeat was Federer's fourth in 10 five-set matches at Flushing Meadows, and first against a player not named Djokovic or Juan Martin Del Potro.

Here is a look back at Federer's five most heartbreaking losses at the final Grand Slam tournament of the year.

#5 2019 Quarterfinals: Dimitrov beats Federer 3-6 6-4 3-6 6-4 6-2

2019 US Open - Day 9

In his 13th quarterfinal at Flushing Meadows, Federer faced world no. 78 Grigor Dimitrov of Bulgaria, a player he had beaten in each of the pair's seven previous meetings.

The winning streak looked set to continue as Federer rode an early break of the Dimitrov serve to take a one-set lead in under half an hour. Failing to capitalise on his momentum, the Swiss dropped serve at 2-3 in the second set, allowing Dimitrov to take a 5-2 lead.

Dimitrov failed to serve out the set at 5-3 as Federer broke back but the Bulgarian clinched the set when the Swiss failed to hold on to his serve in the next game.

Stung by the loss of a set to Dimitrov for only the third time in eight meetings, Federer broke the Bulgarian twice to take a two sets to one lead.

Dimitrov responded by breaking Federer in the first game of the fourth set. Federer survived a 12-minute service game at 2-4 by saving five breakpoints (three of them from 0-40 down) and looked set to get back on serve when Dimitrov stared at three consecutive break points when serving for the fourth set at 5-4.

However, he could not convert and Dimitrov took the fourth set. The missed opportunities would come back to haunt Federer, who left the court for a medical timeout. The Swiss then dropped serve in the opening game of the fifth and then again at 0-2 as Dimitrov took a commanding 4-0 lead.

Federer held his next two service games but was powerless to stop Dimitrov from closing out a 3-6 6-4 3-6 6-4 6-2 win.

#4 2015 Final: Djokovic beats Federer 6-4 5-7 6-4 6-4

2015 US Open Final

For the first time in his US Open career, Roger Federer did not drop a set en route to his 7th title match at Flushing Meadows and his first in six years.

Facing top-seed Novak Djokovic in the final, Federer eyed a shot at history by becoming the first player to win 6 US Open titles in the Open Era. However, the Swiss maestro, who had lost his serve only twice all week, dropped serve as many times in the opening set as Djokovic took a one-set lead.

Federer regrouped by edging a tight second set 7-5 to even the match at a set apiece.

Djokovic let a lead slip in the third set but Federer would regret missing out on two break points at 4-4 as the Serb fought back to take a two sets to one lead. The match looked all but over when Djokovic broke Federer twice in the fourth set to lead 5-2.

The pro-Federer crowd egged the 17-time champion to launch a fightback and the Swiss duly obliged by recouping one of the breaks. However, he squandered three break points to get back on serve at 5-5. A game later, Djokovic sealed his second US Open title.

Federer rued going 4/23 on breakpoints in the match as his wait for an 18th Grand Slam title spilled into a fourth year.

#3 2010 Semifinal: Djokovic beats Federer 5-7 6-1 5-7 6-2 7-5

U.S. Open - Day 13

16-time Grand Slam champion Roger Federer faced familiar rival Novak Djokovic at the 2010 US Open semifinals. In each of their last three US Open meetings (2007 final, 2008 semifinal, 2009 semifinal), Federer had beaten the young Serb.

Federer's win streak against his newest rival at the last Slam of the year looked set to continue when the Swiss took a two sets to one lead. Djokovic took the fourth set to force a decider where Federer held two match points at 5-4 40-15 on the Serb's serve.

Djokovic hung tough to fend off the match points, broke serve for 6-5 and then held to seal the match.

The defeat ended Federer's run of six consecutive US Open finals as the Swiss was denied the opportunity of a first US Open meeting with his arch-rival Rafael Nadal.

It was the first time Federer lost a match at the US Open after having match points. It wouldn't be his last.

#2 2011 Semifinal: Djokovic beats Federer 6-7(7) 4-6 6-3 6-2 7-5

Djokovic was Federer's nemesis for the second straight US Open semifinal

For the fourth consecutive year, Roger Federer faced Novak Djokovic in the US Open semi-final.

Determined to avenge his painful defeat from the previous year and avoid another semifinal ouster against the same opponent at the last Major of the year, Federer took a two-set lead only for Djokovic to storm back into contention by taking the next two sets and forcing a decider.

Games proceeded on serve till 4-3 when Djokovic lost his to love and Federer earned an opportunity to serve for the match. The Swiss arrived at two match points at 5-3, 40-15.

But Djokovic was not done yet. Federer blinked in the most inopportune moment as he failed to convert either of his matchpoints. Djokovic broke back and reeled off the final four games of the match to inflict a second consecutive US Open semifinal heartbreak on his Swiss opponent.

In the process, Djokovic thwarted the possibility of a first Federer-Nadal final at Flushing Meadows for a second straight year.

#1 2009 Final: Del Potro beats Federer 3-6, 7-6(5), 4-6, 7-6(4), 6-2

Del Potro beats Federer in the 2009 US Open final

In his sixth US Open final in as many years, five-time defending champion Roger Federer was an overwhelming favourite against young Argentinian Juan Martin Del Potro.

Federer began strongly, taking the first set for the loss of just three games. Del Potro seemed overawed by the occasion as Federer seemingly took control of the match, serving for the second set and arriving at 30-0.

However, a contentious call at 30-30 perturbed the serene Swiss who lost four consecutive points to drop serve. Del Potro capitalised on Federer's lapses to level the match at a set apiece by taking the tie-break.

The Argentinian then broke Federer in the third set and led 4-3, only for the defending champion to respond by reeling off three games on the trot to take a two sets to one lead.

With the momentum now firmly in his favour, Federer was within two points of a record sixth title when he arrived at 5-4, 30-30 on Del Potro's serve, only for the Argentinian to slam the door shut and force a fifth set.

Federer ran out of steam in the fifth set under a barrage of heavy forehands from Del Potro, as the Argentinian ended the Swiss' five-year Flushing Meadows reign to become the youngest US Open champion since Lleyton Hewitt in 2001.