Meet the US Open women's semi-finalists

Form guide for American Serena Williams ahead of Thursday's US Open semi-final clash against Latvia's Anastasija Sevastova:

17-Serena Williams

Age: 36

Height: 1.75 metres

Plays: Right handed

WTA ranking: 26

Grand Slam titles: 23 (Australian Open 2003, 2005, 2007, 2009, 2010, 2015, 2017; French Open 2002, 2013, 2015; Wimbledon 2002, 2003, 2009, 2010, 2012, 2015, 2016; U.S. Open 1999, 2002, 2008, 2012, 2013, 2014)

Williams passed her toughest test at this year's U.S. Open with flying colours on Tuesday, beating eighth seed Karolina Pliskova in straight sets to reach her ninth consecutive semi-final at Flushing Meadows.

The 36-year-old returned to competitive tennis in a Fed Cup tie in February after giving birth to her first child last year. In July, Williams reached the Wimbledon final but lost to Angelique Kerber.

Williams will be the heavy favorite to lift her first Grand Slam trophy since the Australian Open in 2017 and equal Margaret Court's record of 24 Grand Slam titles.

ROAD TO SEMI-FINALS:

First round: beat Magda Linette (Poland) 6-4, 6-0

Second round: beat Carina Witthoeft (Germany) 6-2, 6-2

Third Round: beat 16-Venus Williams (US) 6-1, 6-2

Fourth Round: beat Kaia Kanepi (Estonia) 6-0, 4-6, 6-3

Quarter-finals: beat 8-Karolina Pliskova (Czech Republic) 6-4, 6-3

19-Anastasija Sevastova

Age: 28

Height: 1.7 metres

Plays: Right handed

WTA ranking: 18

Grand Slam titles: 0

Best US Open result: Semi-finals 2018

Sevastova upset defending U.S. Open champion Sloane Stephens on Tuesday, defeating the third-seeded American in straight sets to reach her first Grand Slam semi-final.

The Latvian claimed her third career WTA title at the Bucharest Open in July, beating Petra Martic in the final.

Sevastova is making a stellar comeback to professional tennis with a career best Grand Slam performance after retiring from the sport in 2013 due to a string of frustrating injuries.

ROAD TO SEMI-FINALS:

First round: beat Donna Vekic (Croatia) 6-2, 2-6, 6-3

Second round: beat Claire Liu (US) 6-3, 6-1

Third Round: beat Ekaterina Makarova (Russia) 4-6, 6-1, 6-2

Fourth Round: beat 7-Elina Svitolina(Estonia) 6-3, 1-6, 6-0

Quarter-finals: beat 3-Sloane Stephens (US) 6-2, 6-3

Form guide for American Madison Keys ahead of Thursday's US Open semi-final clash against Japan's Naomi Osaka:

14-Madison Keys

Age: 23

Height: 1.78 metres

Plays: Right handed

WTA ranking: 14

Grand Slam titles: 0

Best U.S. Open result: Final 2017

Last year's runner-up Keys kept alive hopes of an American champion at Flushing Meadows for the second straight year with a powerful display in against Carla Suarez Navarro to reach the semi-finals.

The 23-year-old has enjoyed a steady season despite not winning a title and is one of two players to reach the last eight or better at three of the four majors.

Keys takes on Naomi Osaka next and leads the Japanese 3-0 in head-to-head meetings. She thumped the 20th seed in the third round at Roland Garros this year.

ROAD TO SEMI-FINALS:

First round: beat Pauline Parmentier (France) 6-4, 6-4

Second round: beat Bernarda Pera (US) 6-4, 6-1

Third Round: beat Aleksandra Krunic (Serbia) 4-6, 6-1, 6-2

Fourth Round: beat Dominika Cibulkova (Slovakia) 6-1, 6-3

Quarter-finals: beat Carla Suarez Navarro (Spain) 6-4, 6-3

20-Naomi Osaka

Age: 20

Height: 1.80 metres

Plays: Right handed

WTA ranking: 19

Grand Slam titles: 0

Best U.S. Open result: Semi-finals 2018

Osaka reached her first Grand Slam semi-final on Wednesday, in only her third appearance at Flushing Meadows, after cruising past Ukraine's Lesia Tsurenko.

Osaka, who was born in Japan but spent most of her childhood in the United States, claimed her first career title at Indian Wells earlier this year.

The 20-year-old is the first Japanese woman in 22 years to reach the semi-finals of a Grand Slam and is looking to become only the second Asian to win a major after China's Li Na.

ROAD TO SEMI-FINALS:

First round: beat Laura Siegemund (Germany) 6-3, 6-2

Second round: beat Julia Glushko (Israel) 6-2, 6-0

Third Round: beat Aliaksandra Sasnovich (Belarus) 6-0, 6-0

Fourth Round: beat 26-Aryna Sabalenka (Belarus) 6-3, 2-6, 6-4

Quarter-finals: beat Lesia Tsurenko (Ukraine) 6-1, 6-1