The 2019 WTA Season is just days away, but before we turn the page on a dramatic season, WTA Insider looks back at the women who drove the biggest stories, trends, and narratives of the 2018 season.

Simona Halep

The World No.1's fingerprints were all over the 2018 season. Anyone who has sat down to make a list of the most memorable matches of 2018 has seen her name come up time after time, playing either star or co-star to the most riveting duels of the year. Whether it was her trio of three-set dramatics at the Australian Open against Lauren Davis, Angelique Kerber, and Caroline Wozniacki, her physical fortnight over the summer in Montreal and Cincinnati, or her gutsy effort to finally win her first major title at Roland Garros, 2018 was the year Halep stepped up and met the moment time and time again. 

Naomi Osaka

The 21-year-old made history in winning two of the biggest titles of the season at the US Open and Indian Wells, each time doing so in dominant style. The scary thing? She's still raw. 

To win Indian Wells, Osaka knocked off Simona Halep, Karolina Pliskova, Daria Kasatkina, Maria Sharapova, Agnieszka Radwanska, Maria Sakkari, and Saschia Vickery, all while dropping just one set en route to her first career title. As if that wasn't impressive enough, days later she would tally her first of two wins over her childhood idol Serena Williams in Miami. 

But it was her New York run that showed off her full arsenal, both physical, tactical, and emotional, to again lose just one set en route to the title. In 11 of the 15 sets she played she lost no more than 3 games, including three bagel sets. And then, amidst the absolute chaos on Arthur Ashe Stadium, Osaka showed the world that she may be soft-spoken, but she is not soft.  

Osaka's historic 2018 saw her rise from No.68 to finish at No.5, all despite her own admission of struggles through both the clay and grass swings. In rewriting the Japanese record books, the charismatic youngster won 83.8% of her career prize money in 2018 alone and looks well on her way to global superstar status. 

Serena Williams

Serena took the court 24 times in 2018, and it was an event every single time. From her comeback at Indian Wells, to her iconic catsuit-clad return to Slam play at Roland Garros, no player dominated the conversation both on and off the court like Serena. It is a credit and a curse of her greatness that making two Slam finals upon her return -in her fourth and seventh tournaments back, no less - feels to many like a disappointment. 

So let's set the record straight: In a season that saw unheralded depth on the women's tour, only Simona and Serena made two Slam finals in 2018. It was an incredible feat and one we don't talk enough about. Two Slam finals!

​​​​​​Caroline Wozniacki

The Great Dane finished 2017 by winning the biggest title of her career at the WTA FInals and it took just two events in 2018 for her to do one better, grabbing her first Slam title at the Australian Open and return to No.1 for the first time in six years. In all, Wozniacki would capture three big titles last season, including big wins in Beijing and Eastbourne. 

After her season finally ended at the WTA Finals in Singapore, Wozniacki revealed she had been diagnosed with rheumatoid arthritis over the summer, making her feats in the fall even more inspiring.

Angelique Kerber

This time last year, Kerber was telling anyone who cared to listen that she had turned the page on a thoroughly disappointing 2017 campaign, which saw her go from World No.1 to afterthought. There were whispers that the German's incredible 2016 season, in which she won the Australian Open and US Open, may have been a one-season deal. 

But after putting in the hard yards in the off-season with new coach Wim Fissette, Kerber showed up in Australia looking fitter than ever and by the time January was over she had a title and another Slam semifinal under her belt. Kerber reinserted herself in the conversation, regularly making the last eight of any tournament she played, before putting together an inspired run to her third major title at Wimbledon and finishing the season ranked World No.2.

Petra Kvitova

The two-time Wimbledon champion's season certainly didn't start off the way she hoped, derailed by a viral infection and losing two of her first three matches. She responded by going on a 14-match win-streak through St. Petersburg and Doha, tying her career-best mark, and then fashioned yet another double-digit win streak during the clay season to win Prague and Madrid. Indoor, outdoor, clay, hard courts, or grass, Kvitova won titles everywhere, and often the hard way, to play out one of the best seasons of her career

Wang Qiang

China has been in search for a successor to the trailblazing Li Na and in 2018, they may have found that woman in 26-year-old Wang Qiang. The Chinese No.1 began her season at No.45 and laid down a breakthrough season, which included her first two tour titles in Guangzhou and Nanchang, and a fall swing through Asia that saw her make the semifinals or better at her last six tournaments, including back-to-back semifinals in Beijing and Wuhan, and a season-capping run to the WTA Elite Trophy Zhuhai final. 

Wang electrified the fall season, tallying wins over Karolina Pliskova (twice!), Garbiñe Muguruza (twice!), Jelena Ostapenko (a double-bagel!), Aryna Sabalenka (snapping Sabaelenka's eight-match win-streak), and Elina Svitolina. Put simply, Wang owned the last two months of the season, finishing the year tied for third in most hardcourt wins in 2018. 

Elina Svitolina

No one has won more titles than Svitolina over the last two years (9) and the 24-year-old has shown year-over-year ranking improvement in every season since she's turned pro. 2018 was the year Svitolina discovered a new mindset and level in her stunning title run at the WTA Finals. Svitolina went undefeated in Singapore, earning wins over Kvitova, Wozniacki, Pliskova, Bertens, and Stephens, finishing the year with an impressive 9-3 record against the Top 10. 

Aryna Sabalenka

2018 is the year "Beast Mode" roared through the WTA. Not unlike Osaka, 20-year-old Sabalenka ripped through the rankings, rising from No.77 to finish at No.13, capturing two Premier titles along the way in Wuhan and New Haven. In fact, more than a handful of pundits look back to the monumental tussle between Sabalenka and Osaka in the Round of 16 at the US Open as the match that, arguably, decided the champion.

By the time the dust settled on the season, Sabalenka's name topped the tour leaderboard in hardcourt wins (35-13), three-setters played (29), and three-setters won (21). She was the youngest Premier champion in 2018 and her awesome display of power left fans wanting more. 

Kiki Bertens

Sometimes players get pigeonholed, sometimes players pigeonhole themselves. Up until 2018, Bertens was perfectly happy being a clay-court specialist. In her own words, Bertens said she may be 20% better on clay, but in her head, she feels 80% better. 

But after a soul-searching off-season that saw her contemplate retirement at 26-years-old, the Dutchwoman rededicated herself and became a Top 10 sniper and all-surface threat. After winning her fifth title - all on clay - in Charleston, and making the biggest final of her career in Madrid (her final against Kvitova was one of the best matches of the season), Bertens went on to make an improbable run to the Wimbledon quarterfinals, beat Halep to win her biggest title in Cincinnati, and add one more title in Seoul. 

When her season finally ended with a semifinal run in her WTA Finals debut, Bertens had gone 12-7 against Top 10 opponents. No one tallied more such wins this season, a feat made even more impressive given her win over Wozniacki in Madrid was her first Top 10 win in nearly two years.

Sloane Stephens

2018 saw Stephens thoroughly consolidate her stunning run to the 2017 US Open title, with another major final at Roland Garros, another big title at the Miami Open, and a run to the final of the WTA Finals in her tournament debut. All that and she was one-half of the match many consider the best tour-level match of the season, her grueling three-set tussle against Halep in the Montreal final. 

Mihaela Buzarnescu

Late-career resurgences are nothing new on the WTA Tour. But a late-career...surgence is beyond rare. In a sport that's always looking for the next new thing, 30-year-old Mihaela Buzarnescu served as a stunning reminder that late-career breakthroughs can still happen

Just two years ago, Buzarnescu was ranked outside the Top 500 and had never played the main draw at a Slam, let alone cracked the Top 100 due to injuries. Suddenly, at 28-years-old, the Romanian's body healed and she proceeded to give her career one last shot. The results were astounding.

After mowing through the ITF circuit in 2017 and qualifying for her first WTA and Slam main draws, Buzarnescu became one of the most dangerous forces in 2018. She earned her first Top 10 win in the spring over Jelena Ostapenko in Doha and made the semifinals or better at five events. In all, she made three finals and won her first WTA title in San Jose. That win would boost Buzarnescu into the Top 20, an astounding rise from being ranked well outside the Top 100 12 months earlier.