As Juan Martin del Potro struggles to his feet, his opponent, Rafael Nadal, approaches to help him. The top-ranked player in the world, Nadal had just won their grueling quarterfinal match. (Tony O'Brien/Reuters)

For a 6-foot-6 Argentine who had run full-tilt for more than three miles trying to subdue world No. 1 Rafael Nadal, this was not the way he wanted to end their nearly five-hour quarterfinal on Wimbledon’s Centre Court: falling awkwardly on a split-second’s change of direction and landing facedown in defeat.

But after gathering his long, aching limbs and rising to his feet, Juan Martin del Potro found Nadal there, having climbed over the net to be first to extend a hand, commend his effort and console with a hug.

Less than an hour later, del Potro appeared in the interview room of the All England Club to answer questions about how he had lost and why. He repeated the process afterward with Spanish-speaking media, having already spoken to three Argentine radio stations immediately after coming off court — giving every sportswriter a chance to probe his emotions and dissect his decision-making as he had done after each match in the run-up to Wednesday’s quarterfinal.

There are no points for grace in tennis, just as there are none for sportsmanship. Expressions of both typically go unremarked. A camera may capture a poignant moment at the net between victor and defeated. But at Wimbledon, as at so many tennis tournaments, displays of civility and sportsmanship unfold long after TV cameras have stopped rolling and still cameras have shifted their focus.

At Grand Slam tournaments such as Wimbledon, players are required to come for interviews, win or lose. But there is no requirement that they do so in good faith. It’s within players’ rights to respond with one-word answers or eye-rolls, to read text messages while journalists pose questions or simply to get up and walk out if they object to tone or topic.

In a similar vein, the post-match handshake is expected, if not required, in the sport. Yet not all are heartfelt. Some are overtly frosty — a “drive-by” finger-touch with minimal contact, as if the opponent has cooties.

It is a lot to ask of the defeated — to look his or her opponent in the eye and extend a hand, then sit for interviews that can feel like inquisitions.

At this Wimbledon, for all the words written about the forehands and fighting spirit of Roger Federer, Nadal and del Potro, their sportsmanship and civility warrant some words as well.

What made their post-match comportment Wednesday so notable was the high stakes of the moment and extreme lengths they had gone to in trying to capitalize on it — Federer against South Africa’s Kevin Anderson on Court One, del Potro and Nadal on Centre Court.

According to IBM’s “Distance Run” tracker, del Potro had run 4,858 meters (just over three miles) in defeat — at top speed to full stop, lurching, reaching, leaping and falling — on damp grass in shoes with little dimples on the soles, rather than cleats, to keep him upright.

Roger Federer answered questions in three languages after Wednesday’s quarterfinal loss to Kevin Anderson. (Florian Eisele/Associated Press)

At 29, the Argentine had lost nearly two years of his career to four surgeries on the ligaments, tendons and joints of his wrists, and only recently had he reclaimed his career-high world ranking of No. 4. His power and confidence restored, del Potro took a two-sets-to-one lead on Nadal, which put him on the cusp of reaching Wimbledon’s semifinals, where he would have been two victories away from a second Grand Slam that would have proved his 2009 U.S. Open championship was no fluke.

But in a fifth set that two-time Wimbledon champion Andy Murray called the best set of tennis he had ever seen live, Nadal proved the more resilient, more resourceful athlete.

“At the moment, I’m feeling sad,” del Potro, looking almost too weary to hold his head upright, said after he was asked to describe his feelings by the first questioner in his post-match interview.

Perhaps in time, the Argentine offered, he could appreciate the effort he had given and the good points he had played — points that brought the 14,000 Centre Court spectators to their feet. He had worked as hard as he could, played his best tennis and come so close. But against Nadal, it was not enough.

“I think Rafa, in the end, deserve to win once again,” del Potro said, patiently recounting the ebb and flow of the match, his thought process at each stage, what he felt in defeat, lying on the ground, when Nadal came to meet him.

“It was kind of him,” he said.

In Federer’s case, the stakes of Wednesday’s quarterfinal were higher, if possible. At 36, the Swiss is nearing the end of his career, even if his performance suggests otherwise. With an eye toward his inevitable decline, he had skipped the clay-court season and scheduled his training around peaking for Wimbledon’s 2018 fortnight, which offered the best opportunity to extend his record 20 Grand Slam men’s singles titles.

For Federer, the self-recrimination following his 2-6, 6-7 (7-5), 7-5, 6-4, 13-11 loss to Anderson must have been profound. He had failed to convert match point in the third set and had come within two points of winning in the fifth — a set that lasted 90 minutes, longer than some entire matches.

Federer had sailed through his previous matches in untouchable form — only to confront the fact, on Wednesday, that he, too, could have less-than-sterling days. He acknowledged this over and over in post-match interviews that went on for nearly an hour.

“Where did you feel you lost control over the match?” the first journalist asked in an almost accusatory tone.

Federer paused a moment. “Honestly, I’m not sure,” he said.

Did being assigned to play on Court One rather than his customary lair on Centre factor in his defeat?

“I don’t think it really mattered, to be honest,” Federer said. “I had my chances and blew them. That’s my problem, really.”

And on he went, providing expansive answers on what went wrong. He had struggled to anticipate Anderson’s serve. He struggled to end points with the “1-2 punch” that is the hallmark of his own, efficient service games — hitting a serve, then a winner off his opponent’s return. Worse, nothing he tried seemed to rattle Anderson.

After fielding questions in English, Federer then gave interviews in French, then a third session in Swiss-German. The gist was the same, but he made sure each journalist got the story.

“It was just one of those days where you hope to get by somehow,” Federer said. “I almost could have. I should have.”