Nadal makes another final

Top seed will play No. 28 Anderson for title Sunday.

NEW YORK — Once Rafael Nadal went from passive to aggressive and got his uppercut of a forehand going, it didn’t take long for him to power into the U.S. Open final.

Closing in on a third title at Flushing Meadows and 16th Grand Slam championship overall, Nadal overcame a so-so start with an overwhelming performance the rest of the way Friday night, taking nine games in a row during one stretch to beat 2009 champion Juan Martin del Potro 4-6, 6-0, 6-3, 6-2 in the semifinals.

No. 1 Nadal will be a significant favorite Sunday against No. 28 Kevin Anderson of South Africa, who beat Pablo Carreno Busta 4-6, 7-5, 6-3, 6-4 to become the lowest-ranked U.S. Open finalist since the ATP’s computer rankings began in 1973. The 6-foot-8 Anderson, who won an NCAA doubles title at the University of Illinois, is equipped with a big serve, certainly, but he only once had even been a quarterfinalist at a major until this week. He’s also lost all four previous matches against Nadal.

“It’s been an amazing season, of course, after a couple of years with some troubles, injuries, tough moments,” Nadal said. “So this year, since the beginning has been a very emotional year.”

He reached the Australian Open final in January, losing to Roger Federer, then claimed his record 10th French Open championship in June.

Save for a less-than-dominant opening set Friday, in which Nadal had nine winners and 10 unforced errors, he barely missed his targets. His numbers the rest of the way: 36 winners, 10 unforced errors.

Hours earlier, Anderson was so excited he celebrated his semifinal victory

as if it made him the champion, stepping on a chair and then a flower box to help him climb into his guest box in the stands.

“I don’t know if it’s appropriate,” Anderson said. “It certainly felt the right thing to do.” Women: New mom Serena Williams, a 23-time major champion, gave Twitter shoutouts Friday to Madison Keys and Sloane Stephens, who will play today in the first all-American women’s final at Flushing Meadows since Williams beat her older sister Venus 15 years ago.

Williams wrote: “There are NO words to describe how proud and how happy I am for @Madison—Keys ... and @SloaneStephens for making the US open finals.

“These amazing women continue to change the game and bring excellence, power, finesse and change to tennis.”

Stephens beat Venus Williams and Keys topped CoCo Vandeweghe in Thursday night’s semifinals.

It was past midnight when Keys mused about the final with Stephens, one of her best friends on tour. It’s the first major final for both.

“I was actually just laughing and thinking, who would have thought in Australia that Sloane and I would be the finalists at the U.S. Open?” Keys said. “Neither one of us were playing at the time, both just having surgeries.”

Stephens, 24, suffered a leftfoot injury at the Rio Olympics. Keys, 22, had surgery on her left wrist in November and then needed further surgery in June.

Keys played two matches at the French Open and two at Wimbledon. Stephens returned at Wimbledon, losing in the first round.

ABBIE PARR / GETTY IMAGES Kevin Anderson used a chair and flower box to climb into his guest box after his victory made him the lowest-ranked man to make a U.S. Open final.