Elise Mertens

Mertens was a doubles finalist at the 2014 QNet Open, alongside Marina Melnikova.

Mertens made her WTA main-draw debut at the 2015 Copa Colsanitas in the doubles event, partnering Nastja Kolar. She won her first WTA doubles title at the 2016 ASB Classic in Auckland, New Zealand, partnering An-Sophie Mestach.

In January, Mertens won the Hobart International, beating No. 3 seed Monica Niculescu in the final. As a result of this she broke into the WTA top 100 for the first time, on 16 January 2017.

After missing the Australian Open qualifying due to her Hobart campaign, Mertens reached the first round of the St. Petersburg Ladies' Trophy through qualifying, and lost to Kristina Mladenovic in straight sets. She then competed at the Dubai Tennis Championships, where, as a qualifier, she beat Tsvetana Pironkova en route to the second round, where she lost to Agnieszka Radwańska. Despite her loss, Mertens reached a new career-ranking of world No. 69. She then lost in the first round of the Malaysian Open to qualifier and eventual quarterfinalist Lesley Kerkhove. After that, she failed to qualify to both Indian Wells and Miami Open, losing in the first round of qualifying to Sachia Vickery and Alison Van Uytvanck, respectively.

At the Ladies Open Biel Bienne, Mertens upset No. 8 seed Monica Niculescu and beat Mona Barthel en route to the quarterfinals, losing there to eventual finalist Anett Kontaveit.

Mertens began the season by becoming the first woman to win back-to-back titles in Hobart. She defeated Mihaela Buzărnescu in the final, defending her title from 2017. Along with Demi Schuurs, she also won the doubles title.[3]

Mertens' season continued with her main-draw debut at the Australian Open. She defeated qualifier Viktória Kužmová, 23rd seed Daria Gavrilova, Alizé Cornet and Petra Martić, all in straight sets, to advance to her first Grand Slam quarterfinal.[4] In the quarterfinal, Mertens achieved her first victory over a top five ranked player, defeating Elina Svitolina, again in straight sets.[5] With her win over Svitolina, Mertens became the third Belgian woman to reach the last four at the tournament, joining former ranking leaders Justine Henin and Kim Clijsters. In the semifinals she lost to Caroline Wozniacki in straight sets.[6]

After her good form in Australia, Mertens had some difficult weeks. She lost respectively in the first round of Doha, Dubai and Indian Wells and in the second round in Miami. In April, she reached her fourth singles final and second of the year at the Ladies Open Lugano in Switzerland. She won the title by beating Belarusian Aryna Sabalenka in straight sets. Together with compatriot Kirsten Flipkens, she also won the doubles title. Two weeks later, she also won the singles title at the Morocco Open by defeating Australian Ajla Tomljanovic in straight sets.

Mertens lost in the second round at Madrid to top seed Simona Halep. She reached the fourth round at the French Open, defeating Varvara Lepchenko, Heather Watson, and Daria Gavrilova before falling again to Halep, who went on to win the title. Seeded second at 's Hertogenbosch, she lost in the second round to Antonia Lottner.

Mertens started off the grass-court season with first-round loss to qualifier Dalila Jakupović in Birmingham. In Eastbourne she lost in third round to Aryna Sabalenka. At Wimbledon, Mertens lost in third round to Dominika Cibulková.[7]

In the American swing, Mertens reached the semifinals in San Jose as well as quarterfinals in Montreal and Cincinnati. In doubles, she lost the final in Cincinnati and won in Wuhan, partnering Demi Schuurs.

Mertens started in Brisbane with a first-round exit against top-10 player and sixth seed Kiki Bertens, she lost the match in three sets.[8] Then in Sydney, she got her first two wins of the season by defeating Katerina Siniaková and Anett Kontaveit before losing in the quarterfinals to Ashleigh Barty.[9]

Defending semifinalist points from last year, she entered the Australian Open as the 12th seed. She won her first and second match in straight sets before falling to 17th seed Madison Keys in the third round.[10] Due to her early exit, her ranking fell to no. 21.

Mertens played Fed Cup in her homecountry for the first time. She was unable to win her two matches against Frenchwomen Alizé Cornet and Caroline Garcia. In the week after, she moved to Doha to play the Qatar Open. She began unseeded at this tournament, but she surprisingly won her first Premier title. On her route to the tournament win, she took the scalp of three top-10 players, including Kiki Bertens, Angelique Kerber and world No. 2 Simona Halep. After her biggest career win to date, she came back in the top 20 at No. 16.

Just two days later, Mertens played in Dubai, where she was placed as 16th seed. She lost in her opening-match against qualifier Zhu Lin after a battle of near three hours.

In March, Mertens started her American tour at Indian Wells. She was 16th seeded but lost in the third round in another battle near three hours against Chinese 18th seed Wang Qiang. Even though she lost early in singles, she was able to win her biggest doubles title to date, alongside Aryna Sabalenka at Indian Wells. Defeating first seeds Barbora Krejčíková and Kateřina Siniaková in the final. Two weeks later, the pair was also able to win the Miami Open doubles title, completing the Sunshine Double. Mertens and Sabalenka became just the fifth doubles pairing in history, and first since Martina Hingis and Sania Mirza in 2015, to complete the Sunshine Double in doubles. These titles took Mertens inside the top 10 in doubles for the first time.

Mertens had a rough start to the clay court season, losing in the opening round of four of her first five tournaments (the exception being a quarterfinal appearance in Morocco where she was upset by the eventual tournament champion Maria Sakkari). Seeded 20th at the French Open, Mertens beat Tamara Zidanšek and Diane Parry to advance to the third round, where she was beaten by 12th seed Anastasija Sevastova in a three hour 18-minute match three-set match, despite winning the first set and holding five match points in the decider. Mertens and Sabalenka performed well in the doubles draw, where they were seeded sixth. The pair reached the semifinals, where they were defeated by the No. 2 seeds and eventual champions Tímea Babos and Kristina Mladenovic.

Mertens performed much stronger in the grass-court season warmup events, making the quarterfinals in Mallorca and the third round in Eastbourne (in both tournaments she lost to the eventual champions, Sofia Kenin and Karolína Plíšková respectively). Seeded 21st at Wimbledon, Mertens advanced to the fourth round for the first time, taking out Fiona Ferro, Monica Niculescu and 15th seed Wang Qiang. However, she was upset by world no. 54 Barbora Strýcová after having a one-set lead. In doubles, Mertens and Sabalenka advanced to the quarterfinals, but were defeated by eventual champions Strýcová and Hsieh Su-wei, the second consecutive Grand Slam the pair lost to the team that would go on to win the tournament.

In the early summer hard-court season, Mertens struggled to replicate her 2018 success, losing her opening round match in San Jose to Kristie Ahn and falling in the second round of Toronto and Cincinnati to Serena Williams and Elina Svitolina, respectively. At the US Open, in September, Mertens was seeded 25th in singles. She defeated Jil Teichmann, Kristýna Plíšková, and former world no. 9 Andrea Petkovic in straight sets, before taking revenge on wildcard Kristie Ahn to reach her second Grand Slam singles quarterfinal, becoming the first Belgian woman to reach the last eight since Kim Clijsters won the title in 2010. She once again squandered a one-set lead, going down in three sets to world no. 15 and the eventual champion Bianca Andreescu. Playing doubles with Sabalenka, the pair reached the final with ease, dropping just one set along the way. The pair then defeated Victoria Azarenka and Ashleigh Barty in the final, winning their first Grand Slam doubles title both as a team and individually. Mertens became the first Belgian to reach a US Open final, as well as winning one, in doubles, and the first Belgian woman to win a Grand Slam doubles title since Clijsters won Wimbledon in 2003. Following the tournament, she reached a new career-high doubles ranking of number 2 in the world.

Mertens failed to register much success in singles during the Asian hard-court swing, outside of a semifinal appearance at the Pan Pacific Open, but reached her fourth doubles final of the year with Sabalenka at the Premier 5-level Wuhan Open, where the pair lost to Duan Yingying and Veronika Kudermetova. Mertens' consistency in both disciplines qualified her to compete in both year-end tournaments. She first competed at the WTA Elite Trophy in singles, where she qualified for the second straight year. Drawn in the same group as her doubles partner Sabalenka, she was beaten in three close sets by the Belarusian before defeating Sakkari in three sets. Placing second in her round-robin group, she failed to advance to her semifinals (Sabalenka won the title). She next competed at the WTA Finals in Shenzhen, playing doubles. The pair fell to Babos and Mladenovic in three sets before recording a straight sets win over the Taiwanese sisters Chan Hao-ching and Latisha Chan. Needing a win over Anna-Lena Grönefeld and Demi Schuurs to advance to the semifinals, they were beaten in three close sets, ending their tournament and season. She finished the year ranked no. 17 in singles and no. 6 in the world in doubles.

Mertens opened the year by reaching the quarterfinals in both Shenzhen, where she was beaten to Elena Rybakina, and Hobart, losing to Heather Watson. Seeded 16th at the Australian Open, Mertens eased through to the fourth round with straight set wins over Danka Kovinić, Watson and Catherine Bellis before being defeated by Simona Halep. In doubles, Mertens and Sabalenka reached the quarterfinals where they lost to Chan Hao-ching and Latisha Chan. After losing early in both Dubai and Doha, Mertens was next scheduled to play in Indian Wells, but the tournament was cancelled and the tour suspended due to the COVID-19 pandemic.

When the tour resumed in August, Mertens lost her opening match in Palermo, but bounced back by reaching her first final of the year at the Prague Open. She then lost to Halep for the second time that year. At the Western & Southern Open, Mertens advanced to her first ever Premier 5 semifinal, where she was beaten by Naomi Osaka in straight sets.

Seeded 16th at the 2020 US Open, Mertens opened her campaign by beating Laura Siegemund in straight sets, followed by two-set wins over Sara Sorribes Tormo and 18-year old Caty McNally. She then caused a huge upset by defeating the second seed and reigning Australian Open champion Sofia Kenin 6-3 6-3, making it to the quarter-finals of the US Open for the second consecutive year.[11] However, she was thrashed in the quarters by former World No. 1 Victoria Azarenka, winning just one game. Mertens and Sabalenka also played doubles together, where they were the defending champions. However, they were beaten in the quarterfinals by the eventual champions Siegemund and Vera Zvonareva.

Mertens continued in good form throughout to the end of the year. She made quarterfinals of Rome losing again to Karolina Pliskova in three sets. She lost in the third round of the French Open to Caroline Garcia. She finished off the year with a final finish at Linz Open losing to long term doubles partner Aryna Sabalenka.

Mertens started off 2021 at the Gippsland Trophy. She beat Mayo Hibi and Caroline Garcia both in straight sets to reach the quarterfinals. There she beat Elina Svitolina in a match tiebreaker to advance to the semifinals, where she received a walkover by Naomi Osaka. She easily won the final defeating Estonian Kaia Kanepi 6-4 6-1. This was her first title in two years.