A summary of Thursday's action at the US Open
World number one Iga Swiatek rallied from a set down to beat Aryna Sabalenka 3-6, 6-1, 6-4 and reach her first US Open final, where she will meet Ons Jabeur on Saturday for the trophy.
After a sluggish start, the Pole came alive in the second set and overcame an early break in the decider by winning the final four games to see off the powerful Belarusian.
"Against Aryna you have to have the energy to push her back and be able to play those fast balls," Swiatek said in an on-court interview.
"In the first set I lacked a little bit of that so I needed to get it together. Drink some energy shots and just kind of go with it. I'm pretty glad that I did that."
With the win Swiatek became the first Polish woman to ever reach the US Open final.
Jabeur became the first African woman of the Open era to do the same earlier in the day.
Both Swiatek and Sabalenka came out tense under the lights on Thursday but the sixth seed settled in first, finding a service rhythm and dialing in her forehand against Swiatek, who has struggled at times in the past against big hitters.
Sabalenka consolidated a break with an ace for 4-2 and captured the first set when she snuck to the net behind a huge forehand and sent a volley past the charging Swiatek.
But Swiatek, who was forced to battle back from a set down in her fourth-round match against Jule Niemeier, raised her level in the second, serving much better and breaking Sabalenka three times to level the contest.
Sabalenka responded early in the third, her confidence growing when her blistering backhand knocked her opponent backwards and onto the court as she raced out to a 2-0 lead.
But the feisty Swiatek refused to give in, breaking back with a backhand winner to level at 4-4 and advanced to her first final in Flushing Meadows when Sabalenka's backhand landed in the net.
The two-time French Open champion Swiatek will gun for her third Grand Slam title when she faces dynamic Tunisian Jabeur, who cruised to her semi-final with a straight sets win over Caroline Garcia.
Swiatek and Jabeur are 2-2 in their four career meetings.
Jabeur trounces Garcia
Earlier in the day, Ons Jabeur executed a stunning 6-1, 6-3 demolition of Caroline Garcia in the first semi-final, ending the Frenchwoman's hot streak to reach her second Grand Slam final of the year.
Garcia had not dropped a set in reaching the last four but immediately ran into problems as Jabeur broke her in the opening game before taking the first set in a blistering 23 minutes, with six aces and 11 winners.
Rolling into her first Grand Slam semi-final on a 13-match winning streak, Garcia was denied the most reliable tool in her arsenal - her big serve - and never had the momentum.
Jabeur, who became the first Arab woman to reach a Grand Slam final at Wimbledon this year and has become known as Tunisia's "Minister of Happiness", shouted with joy after she sent an unreturnable serve over the net for the win.
"It feels amazing. After Wimbledon there was a lot of pressure on me and I'm really relieved that I can back up my results," she said.
"The hard court season started a little bit bad but now I'm very happy that I made it to the finals here."