NEW YORK (AP) — The Latest on the U.S. Open tennis tournament (all times local):

12 a.m.

Novak Djokovic managed to do what Roger Federer could not: beat 55th-ranked John Millman at the U.S. Open.

Djokovic moved a step closer to a third championship at Flushing Meadows and 14th Grand Slam title overall by eliminating Millman 6-3, 6-4, 6-4 in the quarterfinals.

The No. 6-seeded Djokovic, who won Wimbledon in July, had been drawn to face Federer with a semifinal berth at stake. But Millman scuttled that showdown by stunning the 20-time Grand Slam champ in four sets in the fourth round on a hot and humid evening that Federer said sapped his energy and made it hard to breathe.

This one wasn't exactly simple for Djokovic: He only converted four of 20 break points. And he finished with 53 unforced errors.

But he did move on, and now will face Kei Nishikori in the semifinals.

___

11:10 p.m.

U.S. Open tournament director David Brewer says the tournament's hard courts were purposely slowed down "a touch" in response to players noting in recent years that the surface seemed to be speeding up.

Several players have said during the past two weeks that the courts are playing differently this year.

Roger Federer's assessment after his first-round victory was: "This, to me, seems the slowest U.S. Open we've seen in years."

Brewer says that the amount of sand or other granular items can be adjusted to make a court faster.

He adds that he can't recall any attempts to alter court speeds at Flushing Meadows with the intention of helping American players.

No U.S. man has won the singles title in New York since Andy Roddick in 2003, and none has even reached the semifinals since Roddick in 2006.

Last year, all four women's semifinalists were Americans, and two of this year's are, Serena Williams and Madison Keys.

___

10:40 p.m.

The U.S. Open quarterfinal between Novak Djokovic and John Millman has resumed after a brief break at 2-all in the second set so that Millman could change out of his sweat-soaked outfit.

Normally, players are only allowed to head off the court between sets to change what they're wearing.

But Millman asked Djokovic if he'd be OK with a delay after the fourth game.

Djokovic said it was fine, because he needed a bit of a rest.

Play resumed after about a six-minute delay.

___

8:45 p.m.

Madison Keys reached the semifinals at a second consecutive U.S. Open, beating No. 30 Carla Suarez Navarro 6-4, 6-3.

Keys, a 23-year-old American who is seeded No. 14, overwhelmed Suarez Navarro with her powerful serve and groundstrokes, building a 22-10 edge in winners.

Keys faced only two break points, one while serving for the victory in the final game, and saved both.

She has made it to the final four at three of the past five Grand Slam tournaments but is still seeking her first major championship.

Keys was the runner-up to Sloane Stephens at the U.S. Open in 2017, then lost to Stephens in the French Open semifinals this year.

She will face No. 20 Naomi Osaka in Thursday's semifinals. Serena Williams faces Anastasija Sevastova in the other semifinal

___

6:05 p.m.

Kei Nishikori outlasted Marin Cilic in a rematch of the 2014 U.S. Open final, moving into the semifinals with a 2-6, 6-4, 7-6 (5), 4-6, 6-4 victory.

The No. 21 seed gave Japan a men's and women's semifinalist at the same Grand Slam tournament for the first time in the professional era. Naomi Osaka won her quarterfinal in the match that preceded Nishikori's.

Cilic won the 2014 matchup in straight sets but this match resembled their 2010 second-round matchup in Flushing Meadows, when Nishikori rallied for a five-set victory in 4 hours, 59 minutes, the fifth-longest men's singles match by time in U.S. Open history.

This one lasted 4:08 and sent Nishikori into a matchup with No. 6 seed Novak Djokovic or unseeded John Millman.

___

3:10 p.m.

Francesca Schiavone has retired from tennis after a career in which she won the French Open title and three Fed Cup championships with Italy.

Schiavone, 38, said she accomplished both her goals as a player, which were to win at Roland Garros and reach the top 10 in the world. She did both in the same year, with her 2010 French Open title helping propel her to No. 7 that year. She would peak at No. 4 — the highest ever for an Italian woman — in 2011.

She also played the longest Grand Slam match for a woman that year, overcoming six match points to beat Svetlana Kuznetsova 6-4, 1-6, 16-14 in 4 hours, 44 minutes in the fourth round of the Australian Open.

She is now coaching, and says her dream now is to bring a player to a Grand Slam tournament.

___

2:30 p.m.

The draw has been set for the 11th wheelchair tennis competition at the U.S. Open.

Twenty athletes will compete in men's and women's singles and doubles as well as the quad competition, which involves players who have lost some function in at least one of their arms.

Wheelchair tennis has been around for more than four decades with 120 professional events in 80 countries, but only recently become a mainstay all four Grand Slams.

It was first played at the U.S. Open in 2005, but did not have a match in Arthur Ashe Stadium until last year. It will have two more played at the main stadium this week.

American David Wagner, the top-ranked quad player in the world, is attempting to win his fourth U.S. Open quad singles title and his ninth in doubles.

The competition runs from Thursday through Sunday with a total purse of $200,000.

___

1:15 p.m.

Naomi Osaka dominated Lesia Tsurenko 6-1, 6-1 at the U.S. Open to reach her first Grand Slam semifinal.

The No. 20 seed broke Tsurenko in the second game of the match, despite being on the sun-drenched side of the court at Arthur Ashe Stadium and cruised from there. She needed just 26 minutes to win the first set and finished the match in just under an hour.

Tsurenko, who had 31 unforced errors, went up 40-15 in the first game of the second set, but was broken again. She also had three break points in the sixth game of the set, but could not capitalize against the 20-year old.

The 29-year-old Tsurenko, who had struggled with the heat during her three-set win Monday over Marketa Vondrousova, grabbed her legs several times during the match, but did not ask for any medical help.

Osaka becomes the first Japanese woman in a Grand Slam semifinal since Kimiko Date at Wimbledon in 1996.

___

11:30 a.m.

It's another scorching hot day in New York and that means the extreme heat policy is back in effect for the third consecutive day at the U.S. Open.

The policy allows a 10-minute break between the second and third sets of women's singles matches if either player requests one. For men's singles matches, the break would come between the third and fourth sets.

The policy is a rule on the women's tour, but not the men's. U.S. Open officials began putting it in play last week, when temperatures first soared into the mid-90s.

It was already 85 degrees (29.4 Celsius) outside of Arthur Ashe Stadium about a half hour before the opening quarterfinal match between No. 20 seed Naomi Osaka of Japan and Lesia Tsurenko of Ukraine.

___

11 a.m.

Marin Cilic looks for history to repeat in a quarterfinal rematch of the 2014 U.S. Open final.

The No. 7 seed faces No. 21 Kei Nishikori on Wednesday, four years after beating the Japanese player for his first Grand Slam title. Nishikori has won eight of the 14 meetings.

The other men's quarterfinal features No. 6 seed Novak Djokovic against John Millman. The unseeded Australian knocked out 20-time Grand Slam champion Roger Federer in the fourth round to reach his first major quarterfinal.

Djokovic won his 13th Grand Slam at Wimbledon, just after beating Millman 6-2, 6-1 at Queen's Club in their only previous meeting.

On the women's side, American Madison Keys, last year's runner-up, looks to return to the semifinals for the second straight year against Carla Suarez Navarro. No. 20 seed Naomi Osaka of Japan and Lesia Tsurenko of Ukraine are both looking for their first semifinal appearance when they meet in the day's first quarterfinal in Arthur Ashe stadium.

___

More AP tennis coverage: https://apnews.com/tag/apf-Tennis and https://twitter.com/AP_Sports