World number one Iga Swiatek rallied from a set down to beat Aryna Sabalenka 3-6 6-1 6-4 and reach a first US Open final against Ons Jabeur on Saturday.
After a sluggish start, the Pole came back in the second set and overcame an early break in the decider by winning the final four games to see off the powerful Belarusian.
With the win, Swiatek became the first Polish woman to reach the US Open final, and there she will face Jabeur, who became the first North 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.
