Welcome 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. First we head to the green clay of Charleston, South Carolina, where a thrilling 2015 final pitted Angelique Kerber against Madison Keys.

HOW THEY GOT THERE: No.5 seed Angelique Kerber had notched up her third straight Top 10 season finish the previous year, but for all her increasing ability to play a role in top-quality contests, the German still frequently ended up as the bridesmaid rather than the bride. Her 2014 had been highlighted by four losses out of four finals, taking her career record in title matches to 3-9 at this point; she had yet to win a trophy outdoors, and had not done so at Premier level since becoming the Paris 2012 champion.

Moreover, a decent start to 2015 - a quarterfinal in Brisbane followed by a semifinal in Sydney - had abruptly hit the skids. Since Sydney, Kerber had gone 3-7, including a shock Australian Open first-round upset at the hands of Irina-Camelia Begu, a 6-1, 6-1 loss in Antwerp to Francesca Schiavone and a 6-0, 6-3 defeat in Doha to Victoria Azarenka.

In Charleston, the 27-year-old had barely escaped another opening-round exit, needing to come from a set and break down, and then to overturn a 2-4 final-set deficit, before surviving Evgeniya Rodina 3-6, 6-3, 6-4. But by the time Kerber reached her first claycourt final since Bogota 2010, she was ominously battle-sharpened: in the quarterfinals, she had scrapped her way to revenge over Begu, coming from 1-5 down in the first set (saving three set points) and 2-4 down in the second (saving two set points) to emerge a 7-6(3), 7-6(4) victor, and in the semifinals she had snapped a three-match losing streak against defending champion Andrea Petkovic to defeat her compatriot 6-4, 6-4.

Photo by Family Circle Cup/Alice Keeney Photography

While Kerber had struggled in the first quarter of the year, No.7 seed Madison Keys had soared. The 20-year-old's ferocious power had threatened a breakthrough for some time already, and it had arrived in style with her maiden Grand Slam semifinal showing in Melbourne - a run that featured upsets of both Petra Kvitova and Venus Williams, and which marked the American out as the foremost young player to watch in 2015.

An adductor injury had set Keys back afterwards, forcing her to withdraw from both Fed Cup and Acapulco - and she had not been able to rediscover her Australian form immediately on returning, falling in the third round of Indian Wells to Jelena Jankovic and the second round of Miami to Sloane Stephens. However, Charleston had seen Keys catch fire again, eviscerating a series of opponents, all in under 70 minutes, en route to her first clay final. Indeed, only Lucie Hradecka had been able to win more than two games in any set against Keys in a 6-1, 6-4 semifinal loss.

Despite trailing Kerber 1-2 overall, Keys also had the advantage of having won their most recent match 6-3, 3-6, 7-5 in the previous year's Eastbourne final - a high-quality thriller in which her ability to dominate on serve had been crucial to sealing her maiden title.

Charleston: Kerber vs Keys

WHAT HAPPENED: The match would end up as a worthy successor to the Eastbourne final, comparable in scoreline and tightness - though this was not immediately apparent. Kerber shot out of the blocks, breaking Keys immediately and smothering the American's power with tenacious defence and impermeable baseline control - particularly on the biggest points. Keys would break back to level at 2-2 - but this recovery had little impact on Kerber's momentum.

The German, reading the Keys serve magnificently, broke twice more, won a crucial seven-deuce marathon hold to tighten her grip on the set, and a service winner sealed the opening act - and fourth game in a row - on her first set point.

Cleaning up some of her wilder errors and demonstrating greater patience to construct points behind her powerful delivery, Keys showed real fortitude to make the match a contest in a serve-dominated second set. There was no sniff of a break point through the first seven games, and the only break of the set came in the 10th and final game: Kerber had fended off two set points already, but staring down a third found the Keys forehand too hot to handle.

Despite Keys' raised level, Kerber had nonetheless kept a second set that was only decided by a few points close to the end, aided in part by a stellar 83% first serve percentage over the course of the day. But, rattled by the loss of the stanza, Kerber opened the decider with her flattest passage of play of the day as Keys stepped on the gas. Leaking uncharacteristic cheap errors, Kerber conceded serve with a long forehand as Keys raced to a 4-1 lead, just eight points from claiming the title.

Gallery: From Lisicki to Keys: Charleston champions

But Kerber would instead bolster her growing reputation as a player able to flip momentum and mount comebacks out of nowhere, even when displaying sarcastic body language and seemingly out of the match mentally. That occurred once more: down 2-4, Kerber managed to flick a magical backhand pass past Keys at net to carve out a break-back point - and in one instant, she had transformed the final.

Duly taking that opportunity, Kerber would rattle off six of the last seven games. The climax of the match would feature some of the most thrilling rallies of the day - but, repeatedly pitting her forehand against the Keys backhand, Kerber's tactical nous frequently outdid her opponent's power. Moreover, the 27-year-old's serve was near-impregnable at the business end of the third set: from 1-4 down, she would drop just three more points behind her delivery, and reel off the last 11 in a row.

The final statistics would - unsurprisingly - show Keys dwarfing Kerber's numbers in terms of both winners (49 to 17) and unforced errors (57 to 21), but now it was the older player bringing her best tennis to bear when she most needed it. Though Keys seemed to have steadied herself in the face of Kerber's comeback, at 5-5 the home player let slip a 40-0 lead to drop serve with a backhand long. Kerber needed no further encouragement to seal a 6-2, 4-6, 7-5 win and her fourth career title - and first outdoors - with a love hold, chasing down a dropshot on a championship point that left both players on the ground after two hours and 16 minutes of gripping play.

Photo by Family Circle Cup/Alice Keeney Photography

WHAT THEY SAID: Kerber was quick to acknowledge her relief at ending her slump and turning around her record in finals. "It's unbelievable... to win the title here in Charleston after the really difficult weeks that I had... I had last year four finals and I didn't win one, so it's great to actually win this tournament," she gushed.

Having been the only player this week to break the Keys serve even once, Kerber explained that concentrating on her own game plan had been crucial to surviving her opponent's barrage of power. "I was not thinking about [her serve]," she explained. "I was focusing on myself and trying to hit balls deep and get to every single ball. I was more focusing on my game than on her.
"In the third set when I came back I was more aggressive and just going for it, because in the second set I was just trying to cope, and she was going for it in the most important moments. That was the key at the end."

Keys, meanwhile, rued her "nervous" first set, but paid tribute to Kerber's resilience in the third: "At the end she just didn't make any mistakes, and I started making a couple more - and that was really the match... I was up 4-1, but she completely lifted her level, and it totally changed right then. I was so close, but then it also hurts a little bit more."

One particular weapon had been especially effective, said Keys: "She hits really great drop shots, so I was actually kind of surprised that they weren't happening in the first and second set as often. And then in the third I was like, yeah, there they are. OK."

The title, Kerber's first on clay - and indeed outdoors - had also reshaped her attitude to the surface. Though she had reached her maiden WTA final on clay at Bogota 2010, losing to Mariana Duque-Mariño, as well as her second major quarterfinal at Roland Garros 2012, Kerber acknowledged: "It was never my favorite surface." This suspicion, she said, was shifting: "It's changed in the last year... I think it's also good for my game because I'm playing defensive and also being aggressive, so to mix it on clay is, I think, not bad."

Photo by Family Circle Cup/Lightbending 411

WHAT IT MEANT: This result snapped a four-match losing streak in finals for Kerber - and started a winning streak of the same length as she went on to capture a career-best four titles over the course of 2015, adding Stuttgart, Birmingham and Stanford to her trophy cabinet this season. And not only was Kerber winning, but she was doing so in style: each of those finals was a top-quality three-setter that added to her reputation as one of the most likely players on the WTA Tour to be involved in a classic match.

Only Kerber's Grand Slam performances would let her down: failing to progress beyond the third round of any would contribute to her year-end ranking actually falling by one place to World No.7. However, that can be attributed to some disproportionate bad luck with her draws: Roland Garros and Wimbledon both saw her fall to a surging Garbiñe Muguruza in round three, while former World No.1 Victoria Azarenka was her conqueror at the same stage of the US Open - and again, all three losses would be stellar three-set affairs.

In any case, having resolved her difficulties in finals in 2015, Kerber would outshine every other player on the major stage in 2016, a career-best season that saw her collect her first two Grand Slam titles at the Australian and US Opens, and ultimately seal the coveted Year-End World No.1 spot.

Keys, meanwhile, would not reach another final for over a year, and her 2015 results would tail off somewhat from her eyecatching start. In a foreshadowing of her ability to peak on the big stage, though, the only tournaments at which Keys would win three straight matches for the rest of the year were Wimbledon and the US Open, where she made her debut appearances in the quarterfinals and the fourth round respectively. Keys' career thus far has seen the American's best results heavily weighted towards certain events - with the Grand Slams among them but also Charleston, where she eventually claimed the title in 2019.

Kerber would also use the momentum from this triumph to take a stranglehold over the pair's rivalry that Keys has yet to loosen. Their consecutive knife-edge finals might have seemed like a harbinger of a tight rivalry at this point - but instead, Kerber went on to claim the next five meetings without the loss of a set, and she now holds a dominant 9-2 record over Keys overall.

Photo by Family Circle Cup/Alice Keeney Photography