Welcome back to Clay Chronicles, where wtatennis.com will take a look back at some of the most memorable matches from the clay seasons of the past five years. After recapping Charleston's classics and Stuttgart's standards, our retrospective now heads to Madrid, Spain to recount some of the best matches from recent editions of the Mutua Madrid Open. Continuing the countdown is Kiki Bertens’ comeback win over Maria Sharapova in the classic 2018 quarterfinal, where the Dutchwoman claimed a three-set victory en route to her first Premier Mandatory final.

Madrid Rewind:
2015: Serena Williams def. Victoria Azarenka, third round
2016: Dominika Cibulkova def. Agnieszka Radwanska, first round
2017: Simona Halep def. Kristina Mladenovic, final

2018 Madrid highlights: Bertens seals Sharapova in Madrid comeback win

HOW THEY GOT THERE: Coming into the 2018 Mutua Madrid Open, on-the-rise Dutchwoman Kiki Bertens had already won five WTA titles - every single one of them on clay. 

Her most recent win, at the Volvo Car Open in Charleston, was her biggest title to date,and it solidified her as a growing force on tour, following a breakthrough 2016 that saw her reach her first Grand Slam semifinal at Roland Garros. 

But by the end of 2017, Bertens had been pondering retirement, she would later reveal. After hovering around the Top 30 for years, Bertens was burnt out from tour life and media attention - but chose to press on and make some big changes at the urging of then-coach Raemon Sluiter. 

Read more: Coach’s Corner: Raemon Sluiter reveals why Kiki Bertens nearly walked away from tennis

“Would you be able to quit tennis now, sitting at home, and not thinking in three or four years, ‘Maybe I should have done things a little bit differently? Can you live with that?’" Sluiter asked Bertens during the 2017 off-season.

The answer was a resounding “no”, and at the start of 2018 Bertens returned to the courts with renewed purpose. Despite a slow start to the season, Bertens burst to life when the clay season came around, lifting the trophy in Charleston and storming through the draw in the Spanish capital. She booked her spot into the Madrid quarterfinals after taking down No.2 seed Caroline Wozniacki in the round of 16.

Photo by Jimmie48 Photography/WTA

In the quarterfinals, Bertens was pitted against 2014 champion Maria Sharapova, whose own clay court pedigree made her a stern competitor on the surface despite her World No.52 ranking. The Russian had regained her mojo in Madrid, snapping a four-match losing streak with a big win of her own - but she was finding that the long road back to the top was riddled with dangerous new challengers. 

WHAT HAPPENED: The 2014 champion was off to a fast start on Estadio Arantxa Sánchez Vicario, carrying all of her momentum in their quarterfinal and drawing first blood. 

It was Bertens’ first meeting against Sharapova, and the Dutchwoman was struggling to match Sharapova’s pace. Bertens shook off losing the opening set to take an immediate double break lead in the second and leveled the match behind some impressive play from the baseline.

Match report: Bertens seals Sharapova in Madrid comeback win

The 26-year-old broke first in the decider and while she couldn't serve out the match at 5-2, she duly broke right back to secure her first-ever Premier Mandatory semifinal after two hours and five minutes.

Bertens balanced 21 winners to 34 unforced errors and converted seven of 12 break point opportunities, but the biggest difference came behind the first serve: Sharapova won just 53% of those points to Bertens' 70%.

WHAT THEY SAID: Bertens’ newfound self-confidence was on display even during the Dutchwoman’s most dreaded part of any match: the post-match press activities. 

Bertens was honest about the struggle of playing the five-time Grand Slam champion - but highlighted her ability to problem solve during the match.

"I’d never played [Sharapova], but of course when you see her play, you know that she’s hitting the ball so hard," Bertens said in her post-match press conference.

"I didn’t play so well in the first set, and after yesterday, where I played so well, I was a little bit disappointed. That was the most difficult part: to find my game again, and to play some longer rallies."

"I was a little bit struggling in the beginning, with trying to find the solution, like where I can play the higher balls," Bertens continued. "I think how long the match was, I managed to find a way in that, so I’m really proud of myself: that I worked myself into this match, and I could turn it around."

Sharapova herself was far from downcast during her own post-match press conference, highlighting the positives after an encouraging week that saw her reach a Premier Mandatory quarterfinal for the first time since 2015.

Photo by Jimmie48 Photography/WTA

"I think there are definitely a few [positives] that I can take away from this," Sharapova said after the match. "But I also look at these types of matches, I see a lot of things I should be better at, I should improve at. 

“I think it's a combination of, yes, taking the positives, but also being a little tough on yourself and expecting a little bit more from yourself. That's the only way to improve. You can't keep giving yourself a pat on the back.”

WHAT IT MEANT: Bertens went on to reach her first Premier Mandatory final in Madrid, losing out to Petra Kvitova in a three-set final thriller, 7-6(6), 4-6, 6-3. The run propelled Bertens back into Top 20, where she’s now become a permanent fixture, staying inside the Top 20 rankings for just about every week since. 

Photo by Jimmie48 Photography/WTA

The Dutchwoman continued to play great tennis on the red dirt, but then she did something unexpected: Bertens reinvented herself as an all-surface threat, and made a surprise run to the quarterfinals at Wimbledon. 

Read more: ‘Kiki, do you love hardcourts?’ Bertens breaks down her Cincinnati breakthrough

She then went into the hardcourt season, and suddenly Bertens’ all-court success went from being a surprise to being the norm, as she went on to reach the quarterfinals in Montreal before claiming her first hardcourt title in Cincinnati - back then, her biggest win to date. And she did it in style too, taking down hardcourt heavyweights like No.2 seed Caroline Wozniacki, No.5 Elina Svitolina, 8 Petra Kvitova before upsetting top seed Simona Halep in the final. 

Read more: 2018 WTA Most Improved Player of the Year: Kiki Bertens

But Bertens didn’t slow down there, surging to a second hardcourt title at the Korea Open in Seoul, qualifying for her first WTA Finals in Singapore. The Dutchwoman went all the way to the semifinals, ending her season inside the Top 10 for the first time in her career.