Caroline Wozniacki leads the head-to-head against Simona Halep 4-2, including their three most recent matches: the 2015 Stüttgart semifinals and both their meetings last year, in the Eastbourne quarterfinals and the WTA Finals round robin (which the Dane took emphatically, 6-0, 6-2). However, Halep leads the head-to-head on outdoor hard courts 2-1, winning in the semifinals of New Haven in 2013 and the semifinals of Dubai in 2015 - with her only loss coming in the second round of Dubai in 2012, when the Romanian was a qualifier ranked No.50 and Wozniacki was the World No.4.
This is the first time in the Open Era that a Slam final has been contested between two players who have both saved match points en route. Simona Halep saved three against Lauren Davis in the third round and two against Angelique Kerber in the semifinals; Caroline Wozniacki fended off two against Jana Fett in the second round. Halep's run is the first time in the Open Era that a player has reached a major final after saving match points in multiple matches.
The last WTA final to involve players who had both saved match point en route was at 's-Hertogenbosch in 2015, when Camila Giorgi beat Belinda Bencic. Both had saved three match points in their quarterfinals: Giorgi against Yaroslava Shvedova (winning 4-6 6-3, 7-6(9)) and Bencic against Kristina Mladenovic (winning, 7-6(4), 6-7(4), 7-5).
This is the first Slam final between the No.1 and No.2 seeds since the 2015 Australian Open, when No.1 Serena Williams defeated No.2 Maria Sharapova. Sixteen Australian Open finals have been contested between the Top 2 seeds, with eight going to the No.1 (most recently Williams in 2015) and eight going to the No.2 (most recently Lindsay Davenport in 2000).
It is also the third Slam final in the past four to have involved two players who have yet to win a major, following Jelena Ostapenko's Roland Garros defeat of Simona Halep last year and Sloane Stephens seizing the US Open over Madison Keys - but the first time this has happened in Melbourne since 1980, when Hana Mandlikova won the first of four Grand Slams over Wendy Turnbull, 6-0, 7-5.
Simona Halep is the first player to have won multiple overtime matches (past 6-6 in the deciding set) to reach a Grand Slam final since Jana Novotna at the 1991 Australian Open. Novotna beat Shaun Stafford, 6-7(1), 6-1, 8-6 in the third round and Stefanie Graf, 5-7, 6-4, 8-6 in the quarterfinals before falling to Monica Seles in the final. Halep has survived Lauren Davis, 4-6, 6-4, 15-13 in the third round and Angelique Kerber, 6-3, 4-6, 9-7 in the semifinals - the first two overtime matches of the Romanian's career.
The World No.1 ranking will go to the winner of today's final - the first time the No.1 ranking has been at stake in a Grand Slam final since Victoria Azarenka captured it for the first time after defeating Maria Sharapova to win the 2012 Australian Open. Halep would extend a reign that began in October, while Wozniacki would return to the top spot for the first time since January 2012 - which, at six years exactly, would be the longest gap between No.1 stints in the Open Era, beating Serena Williams' current record of five years and 29 days.
Both finalists are contesting their third Grand Slam final. Halep has lost her previous two, both at Roland Garros, in three sets: to Maria Sharapova, 6-4, 6-7(5), 6-4 in 2014 and to Jelena Ostapenko, 4-6, 6-4, 6-3 in 2017. Wozniacki is yet to win a set in a major final, losing the 2009 US Open to Kim Clijsters, 7-5, 6-3 and the 2014 US Open to Serena Williams, 6-3, 6-3.
The last time the No.1 seed won the title at a Premier-level tournament or higher was in October 2016, when Svetlana Kuznetsova was champion in Moscow. The last time this happened at a Slam was also in 2016, when Serena Williams won Wimbledon.
Simona Halep would become the first Romanian winner of the Australian Open ever with victory, and the second Romanian Slam champion following Virginia Ruzici's Roland Garros triumph in 1978. Caroline Wozniacki would become the first Danish Slam winner in history.
This is Caroline Wozniacki's 43rd Grand Slam main draw appearance - only three women in the Open Era had more before winning their maiden Slam (Flavia Pennetta, Marion Bartoli and Jana Novotna). This is Simona Halep's 31st main draw, and a win would make her record the eighth most appearances before a first major.
A win for Simona Halep would extend her winning streak to 12 - the third longest of her career to date. In 2016, she compiled a 13-match run with back-to-back titles at Bucharest and Montréal followed by a semifinal showing in Cincinnati; but the Romanian's longest winning streak came in 2015, when she racked up 14 victories through titles at Dubai and Indian Wells before reaching the Miami semifinals. Caroline Wozniacki's longest winning streak is a 13-match run in 2010 of the Montréal and New Haven titles followed by the US Open semifinals.
The girls' final was also set after Chinese Taipei's Liang En Shuo defeated Italy's Elisabetta Cocciaretto, 4-6, 6-3, 7-6(5) and France's Clara Burel beat Chinese No.1 seed Wang Xinyu, 2-6, 6-1, 6-0. In a parallel with the women's event, Liang - like Simona Halep - has saved match points in multiple matches to reach the final, surviving one against Olivia Gadecki in the first round and two in her semifinal.
There has never been a girls' Slam singles champion from Chinese Taipei, though the country has had two girls' doubles champions: Wang Shi-Ting won Roland Garros alongside Nicole Pratt in 1994, and Latisha Chan lifted the Australian Open trophy in 2004 partnering Sun Sheng-Nan. Liang En Shuo is the second Asian girls' finalist in Melbourne after Indonesia's Wynne Prakusya, who was runner-up in 1998 to Jelena Kostanic, and the first Asian girls' Slam finalist since Sachie Ishizu at Wimbledon 2010. She is bidding to become the first Asian girls' singles champion since Noppawan Lertcheewakarn at Wimbledon 2009.
Clara Burel is seeking to become the first French girls' Slam champion since Kristina Mladenovic at Roland Garros in 2009, and the first to lift the trophy in Melbourne since Virginie Razzano beat Katerina Basternakova in 1999. She is the first French girls' Slam finalist since Caroline Garcia at the 2011 US Open.
Simona Halep's route to the final has been Herculean - as Giri Nathan writes at Deadspin, the Romanian has "weathered everything".
An unusual aspect of Simona Halep's Australian Open experience is that the World No.1 is playing in unbranded clothing, made by a Chinese seamstress based on some designs Halep found online. James Matthey has more on Halep's outfit story at Fox Sports.
For Caroline Wozniacki and Simona Halep in particular, an immense amount is at stake in the final. Jerry Bembry outlines how much for ESPN.com.
ORDER OF PLAY
Click here to find out the full order of play for Saturday in Melbourne.
Find out Simona Halep's thoughts after her punishing, record-making run to the finals.