NEW YORK -- Toward the end of his press conference Sunday, Rafael Nadal suddenly stopped talking and leaned back in his chair. He closed his eyes and grimaced. He started taking unnaturally big breaths.
Then all hell broke loose.
Nadal slid off his chair and lay down on the floor behind a big desk. The International Tennis Federation representative hurriedly cleared Interview Room No. 1 and had the lights killed. Still, cameras and microphones allowed the whole 15-minute drama to be seen and heard.
It was truly extraordinary to witness. Trainers and members of his team rushed to his aid, speaking swiftly in Spanish. Complaining of leg cramps -- the classic symptoms of dehydration -- Nadal received ice and water.
Nadal had just beaten David Nalbandian 7-6 (5), 6-1, 7-5 on a hot and particularly humid day. He was pulled to his feet and walked off the stage under his own power, but his legs were unsteady.
Five minutes later, Nadal returned to say he was fine. As if nothing had happened at all.
"I just have cramping in front and behind," he said. "That's why I, was so painful. That's all."
Later, Andy Roddick downplayed the incident:
"Not to put a dampener on the story, which I know you guys think is really big, but people cramp after matches when you're cold," Roddick said. "It's just something that happens. It's just unfortunate it happened in front of you all. Every single player in there has had that happen before. Every single one.
"What we do, we run around, run miles and miles and miles and miles on the tennis court in nasty weather. You throw nerves in there, I mean, it happens. As long as it doesn't happen during a match, you're fine."
This U.S. Open has already been visited by a record 14 retirements, but this episode memorably underlined how difficult the conditions have been.
Still, there is a winner to be crowned.
If you put $1 on Nadal to win here, the folks at Ladbrokes will give you $4 back if he does. If you're backing Novak Djokovic, it will take 11 bucks to make only $10. This is what happens when you've won 60 of 62 matches.
Rafa never makes it look easy -- some of his early-round matches in New York are about as watchable as late-night infomercials -- but beyond that bizarre turn of events, there is another reason to like his chances:
Nadal, almost quietly with the tsunami of Djokovic coverage, has now won 10 straight matches at the Billie Jean King national tennis center. The 29-year-old Nalbandian came into the match as one of only two men to own a .500 or better record against Nadal. They had split four previous matches and, early on, it looked as if the Argentine -- despite a 0-8 streak against top-10 players -- might take Rafa down.
He was serving for the first set at 5-4, when two things happened: Rafa started hitting his forehand a little bigger, and Nalbandian perceptibly tightened. Nalbandian went for an ill-advised drop shot, then lost the game with a woeful second serve that landed a yard long. By the time they reached the tiebreaker, you knew how it was going to end.
Nalbandian threw in another atrocious double, and at 5-all, Nadal hit a terrific shot behind a scrambling Nalbandian, then picked a serve outside and dropped a forehand into the open court. And that was the extent of the drama.
"I happy about almost everything today," Rafa said. "He was playing fantastic, in my opinion, in the beginning."
Nadal -- about an hour before his postmatch episode -- called it his best match of the tournament so far.
Going forward, watch for those Ladbrokes odds to shift a bit.
2. Must-see TV: How much do the top players watch each other? A lot, according to Djokovic.
"I watch, definitely," he said. "It's part of my job. I enjoy it, to be honest. Mostly that's a job of my coach, to take notes, but I do take mental notes.
"I think more exciting matches are about to come because we're coming into the second week. The top players are playing against each other, so it's going to be good to see."
Djokovic will see shot-making wizard Alexandr Dolgopolov Monday in the fourth round.
3. Briefly noted: Nadal, despite his success, has maintained a relatively low profile in the United States. That is about to change.
Last week, he was introduced as the face of Armani jeans and Emporio Armani underwear. Actually, his abs and cheekbones are the center of attention in the new advertising campaign, featuring images of a chiseled-looking Rafa taken by Steven Klein.
"I am a bit shy," Nadal said. "With underwear, it's always tricky."
Journalistic integrity begs this question: Boxers or briefs?
"I use the briefs," he said.
"To play tennis, it's better white."
4. Saturday Night Fever: Djokovic is a talented mimic. You may remember his spot-on impersonations of Nadal and Maria Sharapova, well, now he's dancing.
There was the Serbian "Kolo" dance earlier this year on the "Tonight Show with Jay Leno," and Saturday evening on Arthur Ashe, Djokovic channeled John Travolta.
"I didn't know what I was doing really," he said later. "I was just moving all over."
Djokovic may have lifted the idea of a post-victory dance from Germany's Andrea Petkovic, who has been doing something vaguely robotic in New York.
"No, it's not like [the] Petko dance," Djokovic said. "Petko has already marked her dance. I have to invent a name for mine."
Greg Garber is a senior writer for ESPN.com.