In 2021, Estonia's Anett Kontaveit became the poster child for the age-old adage, "It's not how your start, it's how you finish." The 25-year-old became the first Estonian to qualify for the Akron WTA Finals Guadalajara after winning four of her last seven tournaments of the season to secure her Top 10 debut.

Here's how Kontaveit's career-best season unfolded: 

Overcoming hard quarantine in Melbourne

Starting the year ranked No.27, Kontaveit opened her season with a loss to eventual finalist Veronika Kudermetova in Abu Dhabi and then found herself among the 47 players who landed in hard quarantine due to close contact upon arrival to Melbourne.

The Estonian emerged from the two weeks and tallied her first final of the season at the Grampians trophy. But the Kontaveit would feel the lingering effects of quarantine for months to come. After making the quarterfinals in Doha, where she lost to eventual champion Petra Kvitova, she posted a Round of 16 showing in Dubai, losing to Sabalenka.

Road to WTA Finals, singles

Road to WTA Finals, doubles

This trend of running up against the tour's top players and narrowly losing out would continue for Kontaveit through the clay season, where her three losses would come to Sabalenka again in the Stuttgart quarterfinals, Maria Sakkari in the second round of Madrid and Iga Swiatek in the third round of Roland Garros. 

"I was working so hard and I kept losing to Top 10 players consistently," Kontaveit told WTA Insider. "I felt like I was doing well, I was playing really good tennis, and I was just falling short to these really good players. I'm trying so hard and it's not working against these players, but it's sort of silly because I was losing to these really good players who were playing really good tennis. 

"But I always have this thing where I always want to do better than what I'm doing. At some point I was thinking, 'OK, maybe I'm just not meant to beat them or something.' This demotivating thought went into my head." 

Eastbourne final rekindles grass success

Kontaveit was playing well coming out of the clay season, but she had little to show for it. Her ranking was still stuck at No.27 and she had parted ways with coach Nigel Sears earlier in the spring.

But the transition to grass sparked a surge, as she powered through a tough draw to make her second final of the season in Eastbourne. En route, Kontaveit defeated Svetlana Kuznetsova, Bianca Andreescu, Viktorija Golubic and Camila Giorgi to make her second career grass-court final. (She won her only WTA title in s'Hertogenbosch in 2017.) 

Summer drought leads to new coaching hire

But Kontaveit's Eastbourne surge would be short-lived. Her 6-3, 6-3 loss to Jelena Ostapenko in the all-Baltic final would kick off a five-match losing streak through the summer. Whether it was a dip in form or the luck of the draw - the losses came to Ostapenko (Eastbourne), Marketa Vondrousova (Wimbledon), Maria Sakkari (Olympics), Jessica Pegula (Montreal) and Ons Jabeur (Cincinnati) - Kontaveit found herself reeling.

That's when Kontaveit brought on Dmitry Tursunov, the veteran ATP player who had coached Aryna Sabalenka into the Top 10. 

"I wasn't sure if I was doing the right thing for some time," Kontaveit said. "I was a little bit lost, I would say. With Dmitry joining the team, I feel like I'm doing the right thing again. I feel like the direction where I'm heading is right again.

"It's just brought this new energy and a little bit more self-belief to my game. It taught me how to be a little bit more positive."

Cleveland title sparks season-ending surge

In their first tournament together in Cleveland, Kontaveit snapped her losing streak with a three-set win over Lauren Davis in the first round and proceeded to march to her first WTA title since 2017. Defeating Caroline Garcia, Katerina Siniakova and Sara Sorribes Tormo en route to the final, Kontaveit finally clinched her second WTA title with a 7-6(5), 6-4 win over Irina-Camelia Begu.

Champions Corner: How Kontaveit rediscovered her joy and got back on track in Cleveland

Kontaveit went into Cleveland sitting at No.30 on the Porsche Race to the WTA Finals. Cleveland was just the beginning of a remarkable sprint to the end of the season to snag the final qualifying spot for Guadalajara. 

Kontaveit wins the biggest title of her career in Ostrava

After a third-round showing at the US Open, where she bowed out to Swiatek, Kontaveit stormed to her second title of the season and the biggest in Ostrava. To win her first WTA 500 title, Kontaveit did not lose a set against a murderer's row of opponents, defeating Sorana Cirstea, Paula Badosa, Belinda Bencic, Petra Kvitova and Maria Sakkari in the final. 

"I think I've always had good shots technically," Kontaveit said. "I don't think there's anything dramatically wrong with my game. It's so much in the head. 

I just think I'm playing in a more positive and more secure way, not doing too much but being aggressive. I think I'm moving great. I'm looking at things in a more positive way, which I think translates in my game."

By the time Kontaveit faced Jabeur in the Round of 16 at Indian Wells, the Estonian was riding a nine-match win streak and had won 16 of her last 17 matches. Jabeur would end her streak with a 7-5, 6-3 win, but Kontaveit's late season surge had put her in the running to sneak the final spot in Guadalajara from Jabeur. 

All Kontaveit had to do was go undefeated for the remainder of the season.

Ten consecutive wins locks in Top 10 debut, WTA Finals qualification

Kontaveit had already tallied five straight wins under the roof in Ostrava and would finish her campaign on a 15-match winning-streak indoors, sealing her Top 10 debut and first WTA Finals qualification with one of the most remarkable season finishes of recent note. 

In Moscow, Kontaveit took home her third title of the year with a battling run to the title. She defeated Garbiñe Muguruza in the quarterfinals and Marketa Vondrousova in the semifinals. She then rallied from 6-4, 4-0 down in the final to defeat Ekaterina Alexandrova, 4-6, 6-4, 7-5. 

"I didn't think anything like this was ever possible," Kontaveit said. "Even after winning Moscow, I came [to Cluj-Napoca] and thought, 'This is such a longshot. What am I even doing? I'm exhausted. This is so hard.'"

It may have been hard, but Kontaveit made it look easy. Winning her fourth tournament in seven events, the Estonian did not lose a set all week in Cluj-Napoca, defeating Simona Halep 6-2, 6-3 in the final. The victory sealed her ticket to Guadalajara as well as history for Estonia and the 25-year-old became the first woman from her country to debut in the Top 10. 

Champions Corner: Behind Kontaveit's incredible season turnaround

In sum, Kontaveit went 19-13 through her first 14 tournaments of 2021. She finished the year going 26-2 over her last seven tournaments, winning four titles to sit behind No.1 Ashleigh Barty for most titles this season, and finishing the best season of her career with a 45-15 record.