Fifth seed Li Na of China beat Russian Ekaterina Makarova 6-4, 6-7 (7-5), 6-2 to become the first Chinese player to reach US Open semi-finals.
"I always try to be the first one," said Li after the match Tuesday. "Of course, the first time in US Open semis, it's exciting. I am really proud of myself."
By advancing into the semifinals, Li refreshed her personal US Open record, reports Xinhua.
The world number six is enjoying one of the best seasons in her career, making quarter-finals in three of the four Grand Slams, the first time for the 31-year-old. She has also reached at least the semi-final stage for three straight WTA tournaments including in Toronto and Cincinnati.
"There were some ups and downs in my previous seasons, and this year I have more consistency," said Li.
Li, well known for her hot temper among Chinese fans, moved in Tuesday's match without losing a single set. She had previously played Makarova for three times, winning all of them.
Li held her serve to level the first set until 3-3, and managed to break in the seventh game thanks to a couple of unforced errors from Makarova. Neither player was able to break in the remainder of the set, ensuring Li takes the lead in the match.
Both players suffered from ups and downs in the second set. They finished with six breaks (three for each) to enter the tiebreaker. Li was leading 3-0 in the tiebreak, but the double fault disturbed her pace. Makarova took advantage to take the tiebreak 7-5.
The final set stood in favour of Li as the top Chinese singles player won four straight games after 2-2 to end the match.
"I was feeling so nervous, from the beginning of the match until the end of the match," said Li.
Li will next face world number one Serena Williams, who won 12 consecutive games to beat Spaniard Suarez Navarro 6-0, 6-0.
"If you only think about your opponent, of course, you already lose the match before you step onto the court," said Li.
In another women's singles quarterfinal, the second seed Victoria Azarenka needed three sets to beat Ana Ivanovic 4-6, 6-3, 6-4.
Former world number one Lleyton Hewitt lost 6-3, 3-6, 6-7 (7-3), 6-4, 7-5 to Russian Mikhail Youzhny in a round of 16 match, which lasted 3 hours 58 minutes.
Hewitt, who outclassed sixth seed Juan Martin Del Potro in an even longer five-set thriller in the second round, was favoured to win again when the fifth set went to 5-5, but Youzhny broke the Australian before eventually winning on his second match point.
Youzhny will play world number one Novak Djokovic, who eliminated Marcel Granollers 6-3, 6-0, 6-0. Third seed Andy Murray came back from one set down to beat Denis Istomin 6-7, 6-1, 6-4, 6-4, to set up a quarter-final against ninth seed Stanislas Wawrinka, who downed number five seed Thomas Berdych 3-6, 6-1, 7-6, 6-2.