LONDON -- As John Isner closed out his Round 2 match at Wimbledon, a full 22 hours after it started the day previous, his old friend Sam Querrey was already back in his temporary London home, having completed his pre-Round 3 practice.

Querrey would have kept half an eye on Isner's progress, but there would be no congratulatory message. "We never talk about tennis, ever," Isner said of Querrey. "So it's more like I'll send him a text and ask him what he had for dinner. Not, 'Hey, good job on your win.'"

Meet two-thirds of an all-American tennis friendship, born on the courts of competitiveness in this lonely sport but now blossomed into an understanding among Isner, Querrey and Steve Johnson, where any sense of rivalry is parked.

Johnson bowed out of these championships Monday, but for the two remaining, it looked to be straightforward on Wednesday afternoon. July 4 was on course to be a day of accomplishment, and then rest. Court 12 was painted in stars and stripes. First, Madison Keys went through comfortably, then Querrey -- who was on Court 12 before Isner -- won in three sets against Sergiy Stakhovsky. Job done. Low-key Independence Day celebrations were being prepared.

Isner looked to be following Querrey's lead, but the fellow giant ended up in tennis purgatory. Two sets up against Ruben Bemelmans, Isner then failed to keep his foot on the neck. As the third set went by, and the fourth was slipping, he grew increasingly frustrated, turned his ire to Hawk-Eye, lamented its accuracy to umpire Mohamed Lahyani and copped a warning. His protestations were all the rage on social media; watchers near and far lap up a tennis meltdown.

It was all square, two sets apiece. Then came the rain, the gloom, and the suspension of play Wednesday evening. By that time, Querrey had ticked off his press duties, his rackets were back in the bag and his attention could be turned to his next opponent, Gael Monfils.

From the end of play Wednesday to returning to court Thursday, Isner had to wait in a double consciousness. He had the remnants of his anger toward Hawk-Eye, the need to sleep, the necessity of focusing on Bemelmans while trying to park thoughts of Round 3. "I'm half asleep, I'm not really asleep," Isner said of Wednesday night. "We have all been there. You have something weighing on you."

On Thursday, they restarted play in the fifth set. Isner soon had to save two match points -- which he did with four consecutive aces to take that game -- and then broke Bemelmans, reacting with a scream of accomplishment, and served the match out to win 6-1, 6-4, 6-7 (6), 6-7 (3), 7-5. Adrenaline was pumping, but if he needs a calming influence over the next few hours with Radu Albot waiting on Friday, then he might well pick up the phone and call Querrey, or Johnson. But it won't be to talk tennis; the understanding of pre-match tension goes unspoken.

John Isner celebrates victory over Ruben Bemelmans. Ben Stansall/AFP/Getty Images

In Querrey, 30, and Isner, 33, you have two American tennis players who had their ghosts, and have put them into various stages of exorcism. Querrey is ahead of Isner in this process and has established himself as a real contender here, having reached the quarterfinals in 2016 and then the semis last year.

Isner came here in a bullish mood: "I do believe that at 33 I'm playing my best tennis," he said after his first-round win, pointing to his Masters triumph in Miami in April.

But mention Isner in this corner of the tennis world and memories pinpoint his epic five-set match against Nicolas Mahut in 2010, which lasted 11 hours, five minutes and ended with the American winning 70-68 in the fifth. It was his only previous five-set victory here.

The spectre of that monumental match does not bother him. "I think especially the casual tennis fan, of course that's what they know me by, and that's fine," Isner said. "But I like to think that since then I have done a lot of good stuff in my career to maybe shed that as the lasting image of my career."

He looked at the plaque Thursday, en route to Court 12, but didn't stop.

Watching in the stands Wednesday and Thursday was his pregnant wife, Madison -- their daughter is expected in September. Occasional encouragement of "C'mon John" caught his attention, and he looked back toward his nearest and dearest as he closed out the match. At one point he just went, in sheer exasperation, "Oh, John." But all the while, his team was the calming presence, his reference point for normality.

John and Madison Isner were married in December, then the dominoes fell and Johnson followed in April with Kendall and Querrey married Abby in June. All were groomsmen at each other's weddings. Isner and his wife used a picture of them together from Johnson's wedding to announce their pregnancy.

Even when they meet on court, Isner distances himself from the word "rivalry," saying, "Honestly, we're too goofy and jovial with each other for it to be a rivalry. It's not one at all."

Isner and Querrey have met six times competitively, Querrey currently leading 4-2.

John Isner did not agree with Hawk-Eye during his Wimbledon second-round match with Ruben Bemelmans. Matthew Stockman/Getty Images)

"You know, it's nice to have such close friends out there," Querrey said of Isner and Johnson. "You know, I'm also close with all the other Americans. But we travel seven, eight months a year, so you want guys you're close with and guys that you feel you can talk to about things outside of tennis. He's a great buddy and a great friend to have on the road with me."

As Isner lives in Dallas, Johnson and Querrey -- both based in California -- spend some time playing tennis recreationally, and have the same coach, Craig Boynton.

"We all do get along so well," Isner said. "We wouldn't be in each other's wedding standing up there beside everyone if we didn't get along so well. We are certainly friends for life."

Isner and Querrey could meet here at Wimbledon if they progress to the semifinals, though Querrey's path runs through Roger Federer at the quarterfinal stage. Isner laughed at that prediction. "Isn't Roger in the draw?!" But even if they do face each other, it will be with a smile and then it will be back to being the two friends, talking about the NFL or when they'll next play golf.

"You know, next time we do play each other, hopefully it's here, but we probably will play each other somewhere down the road," Isner said. "It is what it is, but it's not a rivalry at all."