Little did Federer know that, when he waltzed past Alexandr Dolgopolov of Ukraine, 6-3, 6-1, in 1 hour 1 minute, he would have time to get treatment, take a shower, meet the press, get a bite to eat, get home in time to wake the twins from their nap … and still get to see lots of the second semifinal.
It took 2 hours 23 minutes, and probably lots of the fuel out of Djokovic's tank. He may be able to bounce back in Sunday's final just fine. If he doesn't, Federer might consider sending a portion of the $1-million winner's check to Isner's favorite charity.
Djokovic was clear afterward he didn't think his long match against Isner would be a factor in Sunday's 2 p.m. final. But then, he wouldn't say so, and give away a psychological edge, even he felt that way. Nor would he admit two other long three-setters in this event would have any effect.
"I don't feel that I am exhausted," he said. "I have worked to get myself into good physical shape."
Mental shape might be the bigger issue.
Twice, Djokovic served for the match in the second set. Twice, a fired-up Isner broke back. The No. 2 player in the world doesn't often serve for the match twice and fail both times. It was stunning, and so was the manner in which Isner pulled off the two breaks.
He raised his game, his energy, his body language. On the first break, with Djokovic serving at 5-4, he took a serve, cranked it back and charged the net. That got him in position for a winning volley, and when he made it, he pumped his fist and waved his arms at the sold-out crowd in the 16,100-seat stadium. They waved and screamed back.
He turned up the heat again with Djokovic serving at 6-5, and got the fourth consecutive service break with two huge forehands that put Djokovic back on his heels. At love-40, he netted a forehand.
That meant real trouble for the Serbian star.
"When you get into a tiebreaker with John Isner," Djokovic said, "whoever you are, you are not the favorite."
Big servers are always the favorites in tiebreakers because their serves create easy points. Isner, at 6-foot-10, is the ultimate big server.
And so, with the suddenly pro-U.S. player crowd having a fire lighted under it, chanting, "Here we go, Isner, here we go," Isner blasted Djokovic off the court in the tiebreaker, finishing it with a 118-mile-an-hour ace.
Afterward, Isner said he played "a terrific tiebreaker." Nobody, especially Djokovic, would argue.
They started the third set at about the 1 hour 55-minute mark of the match. Federer probably had his twin daughters on his lap in front of the TV by then.
Had Isner won, it would have produced a carbon copy of the 2012 final, when Federer won his fourth title here. Isner had beaten Djokovic in the semifinal that year.
But this time, a frustrated Djokovic was gathering himself for a third set, despite slamming his racket to the court in anger in the first game.
"I managed to regroup…" he said. "The next point, I was back in the game, where I needed to be."
He was also in the kind of control that this six-time major winner is used to. He broke Isner's serve in the fourth game and never looked back. Match point was a routine serve into Isner's body.