After a slow start, Rafael Nadal needed only 101 minutes to win the final three sets against Juan Martin del Potro. (Robert Deutsch/Usa Today Sports)

The barrage that emerged from Rafael Nadal midway through Friday night was whooshing, fearsome and almost undiluted. It transformed Juan Martin del Potro from a brutal semifinal opponent with a one-set lead to some bedraggled dude who looked like he might need a nap. It zoomed by in three sets and 101 minutes with zero available pillows. Had you gone to a concession stand, you might have missed a big chunk of it.

The 4-6, 6-0, 6-3, 6-2 score that it wreaked set up a reality both familiar and unforeseen on New Year's Day. In a year that began with Roger Federer and Nadal coming off breaks of six months and three months, supposedly wading back into the top tiers of the game in their 30s, the four Grand Slams titles look like they will go Federer, Nadal, Federer, Nadal.

That's because, while Nadal has a further task ahead Sunday afternoon, he has a look on his face and in his game that suggests the emphatic running-over of anyone who dares stand across. And the last person with that role will be Kevin Anderson, the 31-year-old, 32nd-ranked South African who has played Nadal four times and won one set out of 10 and who became one of the happiest people in all New York when he found his first Grand Slam final, with his 4-6, 7-5, 6-3, 6-4 win over Pablo Carreno Busta in the opening semifinal.

Much as del Potro, the 2009 U.S. Open champion, had done Wednesday night in besting Federer in four sets, he assembled a first set of considerable wherewithal. His notorious forehand rang through Arthur Ashe Stadium as it tends to do around the world, and it got no sabotage from his backhand. He broke Nadal in the fifth game. He held serve for the set with a monster opposite-field forehand that screamed behind a wrong-footed Nadal. He carried along the knowledge of his respectable record (5-8) against Nadal, his dramatic win over the Spaniard last year at the Olympics, his 6-2, 6-2, 6-2 mauling of Nadal in the 2009 U.S. Open semifinals.

He made it look like the final might go contested between his 6-foot-6 and Anderson's 6-foot-8.

The evening ahead looked long and loud.

Then came the whoosh.

Nadal changed strategy. His uncle and longtime coach, Toni Nadal, credited him with "beginning to attack, taking very good decisions." The decisions involved variation rather than just testing del Potro's backhand. "I started to understand a little bit what I needed to do to try to be a little bit more unpredictable because he was waiting for me on his backhand side," Nadal said.

He started running around the court as if there were three of him, with the power and angles that have brought him 15 Grand Slam titles, including 10 at the merciless French Open and two here (2010, 2013). He won 25 of the 33 points in a second set in which he mixed 13 winners with one unforced error. He won 31 of 53 points in the third and 25 of 37 in the fourth. He blasted stuff into corners and lines. He looked almost miffed. His shots "came too fast from both sides," said del Potro, who felt his backhand wither. Nadal seemed to take whatever fatigue del Potro had lingering from his fourth-round escape of Dominic Thiem and his passage through Federer and magnify it. The "Delpo" chants in the audience grew more occasional and helpless.

"I don't feel like I made many mistakes after that first set," Nadal said, and that stat sheet said 10 (against 36 winners). Clearly, Nadal would take his 15-7 record in Grand Slam finals into a 23rd chance at such a rare occasion.

There, he will find a guy giddy at his first, a guy who just joined a wee club. In the 64 final slots available in the 32 Grand Slams this decade, 53 have gone to four men (Federer, Nadal, Novak Djokovic and Andy Murray) and four of the others have gone to Stan Wawrinka. That has left room for only Marin Cilic twice, then one meager gift each for Robin Soderling, David Ferrer, Kei Nishikori, Milos Raonic and now Anderson.

"I felt deep inside I always had a chance," said Anderson, who got to his 34th Grand Slam tournament here with only one previous quarterfinal qualification (at the 2015 U.S. Open) and a three-set dismissal from Wawrinka then. The path had been so long, with various injuries lending uncertainty last year, that when he clinched his first semifinal, he went into the stands to hug his team, a province normally reserved for champions.

He had just become the first South African in a Grand Slam final since the 1984 Australian Open and Kevin Curren who, like Anderson, had a serve that would not be fun to return. That same Curren, as a naturalized American, had stormed to the final in one of the most famous Wimbledons, that of 1985, when he destroyed both John McEnroe and Jimmy Connors to reach a final opposite 17-year-old Boris Becker. Hall of Fame journalist Bud Collins wound up asking Curren, "Could you imagine that you would come into Wimbledon and beat McEnroe and Connors and not win the title?"

"Not in my wildest dreams," Curren said, smiling.

"Definitely knew about it," Anderson said, "and I think for me the biggest idol was Pete Sampras growing up. Obviously, he was from the U.S. And right behind him, watching Wayne Ferreira [of South Africa, a two-time Grand Slam semifinalist] growing up, that was more sort of in my teenaged years. From a South African standpoint, he was definitely somebody I looked up to a little bit more. I mean, I have met Kevin several times. It was a little young for me in terms of watching too much of his playing."

Anderson, born in 1986, and an NCAA doubles champion at the University of Illinois, came through the barren half of the draw in a U.S. Open lacking Djokovic, Murray and defending champion Wawrinka, all injured. Anderson commendably beat players ranked 534th, 255th, 61st, 40th, 21st and 19th, including American Sam Querrey in a quarterfinal that ended at 1:51 a.m.

Against Carreno Busta in an all-debutant semifinal, he whacked 22 aces to Carreno Busta's one (with a fastest serve of 135 mph) and struck 58 winners to 21. "Definitely amazing feeling being in this position," Anderson said, "and have worked very hard to get here."