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 recent history. In this installment, we tour the last five years in Morocco, where Marrakech and Rabat hosted the Grand Prix de SAR La Princesse Lalla Meryem, a mainstay of the clay-court season since it debuted in Casablanca in 2001.

2015 second round: Kristina Mladenovic def. Garbiñe Muguruza, 7-6(4), 7-6(6)

For the third consecutive season, the Grand Prix de SAR La Princesse Lalla Meryem took place in Marrakech, and rising star Garbiñe Muguruza was the No.1 seed that week, having popped into the Top 20 for the first time at the end of the previous season and taking a wildcard into the clay-court event.

Kristina Mladenovic, though, was ready for a battle in their second-round encounter, as the Frenchwoman's ranking was on the upswing as she tried to reclaim her Top 40 position she had held for a time two years prior.

Two grueling sets, each of which took over an hour, would follow as the combatants fought tooth and nail for the victory. Muguruza broke Mladenovic in the Frenchwoman's first two service games for a 3-0 lead, but the unseeded player stormed back from the double-break deficit. In a decisive tiebreak, Mladenovic cruised to a 5-1 lead and held on to 7-4, snatching the first set from a dire position.

The second set had fewer wild swings, with Mladenovic twice going up a break and Muguruza immediately reclaiming equilibrium each time. Having failed to reach match point when serving for the victory at 6-5, Mladenovic would have been forgiven for faltering in the second-set tiebreak, but the French player hung on. After six minibreaks on the way to 6-6, it was Mladenovic who claimed the final two points to notch the upset win.

Mladenovic would pull off another upset over the Spaniard in their next meeting, when she defeated defending champion Muguruza in the 2017 Roland Garros round of 16, thrilling her homeland crowds. The third time would be the charm for Muguruza, though, as she defeated Mladenovic in the 2019 Monterrey quarterfinals on her way to the title.

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2016 quarterfinals: Kiki Bertens def. Yulia Putintseva, 6-3, 6-7(4), 6-3

In 2016, the Grand Prix de SAR La Princesse Lalla Meryem returned to Rabat for the first time in a decade, and the event was marked by a two-and-three-quarter hour slugfest between two of the WTA's future clay-court experts.

Over the last few years, tennis fans have become accustomed to Kiki Bertens at the very top of the game, but the Dutch player was barely inside the Top 100 by only a handful of ranking points when Rabat kicked off in 2016.

Her quarterfinal opponent, Yulia Putintseva, had been a junior stalwart but had yet to have her WTA breakthrough, beginning the event at a career-high ranking of World No.53. The duo knew each other well coming into the clash, though -- they had played four previous times, in WTA main draws, WTA qualifying, and Grand Slam qualifying, with Bertens holding a 3-1 head-to-head edge.

As their fifth battle commenced, Bertens eked out a critical 18-point game, saving three break points in the process, to hold for 4-2 in the opening set, eventually taking the one-set lead. Putintseva, though, struck back in the following frame; despite failing to serve out the set at 5-4, the Kazakh leveled the match by taking the tiebreak 7-4.

Kiki Bertens at 2016 Roland Garros.

Photo by Getty Images

In the end, though, it was Bertens who broke Putintseva three times in the decider to ease to the three-set victory and book a spot in her first semifinal of the season. The powerful Dutchwoman slammed seven aces on the clay to knock out Putintseva, but she faltered in the next round, squandering a match point during her semifinal defeat to Marina Erakovic.

Nevertheless, the match was a harbinger of great things to come at 2016 Roland Garros, as both players had their Grand Slam breakthroughs mere weeks later. Putintseva slid into her first-ever major quarterfinal in Paris, while Bertens powered to her maiden Slam semifinal. Only World No.1 Serena Williams could stop them, as the American superstar ended their Roland Garros runs in back-to-back tests.

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2017 final: Anastasia Pavlyuchenkova def. Francesca Schiavone, 7-5, 7-5

Hot streaks were on the line in the 2017 Grand Prix de SAR La Princesse Lalla Meryem final, as top seed Anastasia Pavlyuchenkova and wildcard Francesca Schiavone were aiming for 'perfect 10's.'

Schiavone, the 2010 champion and 2011 finalist at Roland Garros, had seen her ranking dip outside of the Top 100, but once she hit the clay, she customarily turned her year around, winning the title in her first 2018 event on the dirt in Bogota without dropping a set. After three weeks off, the Italian lined up in Rabat, where she carved her way to the final holding a nine-match winning streak.

Pavlyuchenkova, though, had also won nine consecutive matches at WTA events by the time she reached the Rabat final. The No.1 seed had notched her ninth career title at Monterrey one month prior, overcoming World No.1 Angelique Kerber in the final, meaning someone would win a 10th straight WTA match and a second straight title on Sunday.

Schiavone was twice up a break in the first set, but the powerful Pavlyuchenkova steered her way back to the forefront. The Russian broke Schiavone in the final game of the opening frame to earn the one-set lead, claiming nearly two-thirds of points returning the Italian's second service.

The second set was also closely contested, but once more, it was Pavlyuchenkova who came out on top in crunch time. For the second set in a row, the Russian broke Schiavone at 6-5, as the hard-fought battle unfortunately ended with a double fault by the Italian on Pavlyuchenkova's first match point. Pavlyuchenkova fired 26 winners in the clash.

Pavlyuchenkova had attained two 'perfect 10's' -- a tenth straight win at WTA events, giving her a tenth career WTA singles title. The Russian would go on to pick up a third singles title of 2017 at Hong Kong in October, and she finished the season ranked World No.15 -- her best year-end ranking to date.

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2018 first round: Hsieh Su-wei def. Bethanie Mattek-Sands, 3-6, 7-6(3), 6-1

Hsieh Su-wei had a renaissance in 2018, as the player from Chinese Taipei began the year outside of the Top 100 but had clawed her way back into the Top 60 by the Grand Prix de SAR La Princesse Lalla Meryem, thanks to a semifinal run in Auckland and a return to the fourth round of the Australian Open for the first time in ten years.

However, up to that point, Hsieh had yet to make a deep singles run on clay at WTA level, having reached only one WTA singles quarterfinal on the surface through 2017. A tricky first-round match would follow for the No.8 seed as she aimed to crack the code on clay in Rabat.

Hsieh's opponent was Bethanie Mattek-Sands, who entered the tournament on a protected ranking. It was Mattek-Sands's third singles event back on tour after suffering a devastating knee injury at Wimbledon nine months prior. With opening-round losses at Miami and Charleston to start her comeback, the American was on the hunt for a win.

The battle between former WTA Doubles World No.1 players started with Mattek-Sands dropping serve in the opening game, but she quickly took control of the first set, breaking Hsieh in the double-hander's first two service games for a 3-1 lead. The American moved to a one-set lead as Hsieh's surge seemed to hit a snag.

The second set favored the returners as they combined to convert six of 13 break points through 4-4. But the last four games of the frame were suddenly easy holds as the pair moved into a tiebreak. It was in the breaker where Hsieh's 2018 form asserted itself, as she clinched it 7-3, gritting out the set without having to face a match point. After that, Hsieh zoomed to victory, claiming the decider in just over half an hour.

Outlasting Mattek-Sands proved to unlock Hsieh's clay play, and the Chinese Taipei star would go on to post a career-best showing on the dirt that week, advancing to her first-ever clay-court semifinal before falling to eventual champion Elise Mertens. Hsieh capped off her singles year by winning her first WTA singles title in six years at Hiroshima in September and finishing in the Top 30.

2019 quarterfinals: Maria Sakkari def. Elise Mertens, 6-4, 7-6(2)

Elise Mertens came into the 2019 Grand Prix de SAR La Princesse Lalla Meryem as the top seed and defending champion, having defeated Ajla Tomljanovic in the 2018 final for her fourth career WTA singles title. The Belgian started off her title defense with a flourish, dropping just four games in each of her first two matches en route to the quarterfinals.

Standing in the Belgian's way in the elite eight was No.6 seed Maria Sakkari, who had also breezed to the quarterfinals, dropping just ten games in her first two matches. The Greek had already picked up her season as the tour hit the clay courts, reaching her first quarterfinal of the year earlier in the month in Charleston.

The two 23-year-olds had already played five times at ITF and qualifying levels, but this was their first encounter at a WTA event, and both were eager to attain victory. A service break in the first game of the tilt went the way of Mertens, but Sakkari immediately tied up the affair before breaking the Belgian at 5-4 for a one-set lead.

2019 Rabat highlights: Sakkari knocks out defending champ Mertens

The second set was topsy-turvy, as Sakkari earned the early break this time around, before Mertens captured the momentum and reeled off four straight games to lead 4-2. Undaunted, Sakkari fought back, breaking Mertens on her third chance of the game to reach parity at 4-4.

The duo advanced to a second-set tiebreak, where Sakkari dominated, racing to a 7-2 victory in the breaker. The Greek had upset the No.1 seed to reach her first semifinal of the season, ending Mertens's seven-match winning streak at the tournament in the process.

Ranked World No.51 at the time, Sakkari's quarterfinal win served as a springboard. She went on to claim her first WTA singles title two days later, defeating Johanna Konta in the Rabat final, and by season's end Sakkari was knocking on the door of the Top 20, which she entered for the first time in early 2020.