section_path: Career/2021: Doubles No. 1, singles No. 2
section_name: 2021: Doubles No. 1, singles No. 2
paragraph_text: 2021: Doubles No. 1, singles No. 2
  
  Sabalenka entered 2021 on a nine-match winning streak and participated in her first tournament at the Abu Dhabi Open as the fourth seed. She defeated Polona Hercog in straight sets, coming back from a 5–2 deficit in the first set, and then defeated Ajla Tomljanović and Ons Jabeur to reach the quarterfinals, similarly in straight sets. She beat Elena Rybakina in the quarterfinals, where she dropped her first set of the week before defeating Maria Sakkari in straight sets. In the final, Sabalenka defeated first-time finalist Veronika Kudermetova in straight sets, losing just four games in total. The run to the title at Abu Dhabi extended her winning streak to 15 matches and catapulted her to a new ranking of No. 7.
  
  Sabalenka went into the Australian Open looking to make a Grand Slam singles quarterfinal for the first time in her career. In three sets, she was defeated in the fourth round by 23-time Grand Slam champion Serena Williams. Sabalenka won the doubles competition with Elise Mertens. By winning the title, Sabalenka ascended to world No. 1 in the doubles rankings for the first time in her career on 22 February 2021.
  
  As defending champion at the Qatar Open in Doha, and after receiving a first-round bye, Sabalenka was defeated in her first match by eventual finalist Garbiñe Muguruza in three sets. At the Dubai Tennis Championships, in her first tournament since becoming No. 1 in doubles, Sabalenka and Mertens received a bye in the first round. They lost their opening match to Jessica Pegula and Bethanie Mattek-Sands. Sabalenka cruised through to the quarterfinals in the singles event, defeating 15th seed Anett Kontaveit along the way, before losing to Muguruza for the second time in as many weeks, again in three sets.
  
  Sabalenka won the title at the Madrid Open, facing Ashleigh Barty in the championship match. It was a rematch of the 2021 Porsche Tennis Grand Prix final, two week earlier, as Sabalenka faced her vanquisher, world No. 1 Ashleigh Barty. As a result of her fourth WTA 1000 title, she entered the top 5 rankings in singles at world No. 4.
  
  Sabalenka and compatriot Victoria Azarenka won the doubles event at the German Open, defeating the top-seeded pair of Demi Schuurs and Nicole Melichar.
  
  Seeded second at Wimbledon, Sabalenka reached her first Grand Slam quarterfinal and semifinal, defeating 18th seed Elena Rybakina and 21st seed Ons Jabeur in straight sets, respectively. She then lost her semifinal match against Karolína Plíšková in three sets. As a result of her performance at Wimbledon, she reached a career-high ranking in the world No. 3 in the WTA singles rankings. Sabalenka became the third Belarusian woman to reach the last four of Wimbledon following Natasha Zvereva in 1998 and Victoria Azarenka in 2011 and 2012.
  
  Sabalenka continued her season at the Canadian Open in Montreal. She reached the semifinals but lost to Karolína Plíšková, in straight sets. She then lost her opening-round match against Paula Badosa at the Cincinnati Open. Despite the loss, Sabalenka reached a career-high ranking of world No. 2.
  
  At the US Open, Sabalenka reached her second consecutive (and second overall) major semifinal following wins over Danielle Collins, Elise Mertens, and Barbora Krejčíková. In the semifinal, she lost to Leylah Fernandez in three sets.
  
  Due to a positive COVID-19 test, Sabalenka was not able to play at Indian Wells.
  
  Sabalenka entered 2021 on a nine-match winning streak and participated in her first tournament at the Abu Dhabi Open as the fourth seed. She defeated Polona Hercog in straight sets, coming back from a 5–2 deficit in the first set, and then defeated Ajla Tomljanović and Ons Jabeur to reach the quarterfinals, similarly in straight sets. She beat Elena Rybakina in the quarterfinals, where she dropped her first set of the week before defeating Maria Sakkari in straight sets. In the final, Sabalenka defeated first-time finalist Veronika Kudermetova in straight sets, losing just four games in total. The run to the title at Abu Dhabi extended her winning streak to 15 matches and catapulted her to a new ranking of No. 7.
  
  Sabalenka went into the Australian Open looking to make a Grand Slam singles quarterfinal for the first time in her career. In three sets, she was defeated in the fourth round by 23-time Grand Slam champion Serena Williams. Sabalenka won the doubles competition with Elise Mertens. By winning the title, Sabalenka ascended to world No. 1 in the doubles rankings for the first time in her career on 22 February 2021.
  
  As defending champion at the Qatar Open in Doha, and after receiving a first-round bye, Sabalenka was defeated in her first match by eventual finalist Garbiñe Muguruza in three sets. At the Dubai Tennis Championships, in her first tournament since becoming No. 1 in doubles, Sabalenka and Mertens received a bye in the first round. They lost their opening match to Jessica Pegula and Bethanie Mattek-Sands. Sabalenka cruised through to the quarterfinals in the singles event, defeating 15th seed Anett Kontaveit along the way, before losing to Muguruza for the second time in as many weeks, again in three sets.
  
  Sabalenka won the title at the Madrid Open, facing Ashleigh Barty in the championship match. It was a rematch of the 2021 Porsche Tennis Grand Prix final, two week earlier, as Sabalenka faced her vanquisher, world No. 1 Ashleigh Barty. As a result of her fourth WTA 1000 title, she entered the top 5 rankings in singles at world No. 4.
  
  Sabalenka and compatriot Victoria Azarenka won the doubles event at the German Open, defeating the top-seeded pair of Demi Schuurs and Nicole Melichar.
  
  Seeded second at Wimbledon, Sabalenka reached her first Grand Slam quarterfinal and semifinal, defeating 18th seed Elena Rybakina and 21st seed Ons Jabeur in straight sets, respectively. She then lost her semifinal match against Karolína Plíšková in three sets. As a result of her performance at Wimbledon, she reached a career-high ranking in the world No. 3 in the WTA singles rankings. Sabalenka became the third Belarusian woman to reach the last four of Wimbledon following Natasha Zvereva in 1998 and Victoria Azarenka in 2011 and 2012.
  
  Sabalenka continued her season at the Canadian Open in Montreal. She reached the semifinals but lost to Karolína Plíšková, in straight sets. She then lost her opening-round match against Paula Badosa at the Cincinnati Open. Despite the loss, Sabalenka reached a career-high ranking of world No. 2.
  
  At the US Open, Sabalenka reached her second consecutive (and second overall) major semifinal following wins over Danielle Collins, Elise Mertens, and Barbora Krejčíková. In the semifinal, she lost to Leylah Fernandez in three sets.
  
  Due to a positive COVID-19 test, Sabalenka was not able to play at Indian Wells.