Monica Niculescu (born 25 September 1987) is a Romanian professional tennis player. She has been ranked by the WTA as high as No. 28 in singles and No. 11 in doubles. She has won three singles and ten doubles titles on the WTA Tour, one singles and three doubles titles on the WTA Challenger Tour, as well as 19 singles and 22 doubles titles on the ITF Women's Circuit.

She was ranked within the top 30 for several years in singles. Niculescu entered the Grand Slam doubles final at Wimbledon 2017 tournament, together with Chan Hao-ching. She reached the quarterfinals in doubles in all Grand Slam championships. In WTA 1000 tournaments, she got into three finals (doubles), six semifinals (five in doubles), and 12 quarterfinals (11 in doubles). In singles, her best Grand Slam performance is reaching round four, which she did at the 2011 US Open and 2015 Wimbledon Championships.

Early life Niculescu was born in Slatina but moved to Bucharest when she was age four. Her mother Cristiana Silvia is a pharmaceutical sales representative, and her father Mihai Niculescu is an engineer. She has an older sister, Gabriela, who has also been a professional tennis player.

Junior career

Before age 18, Niculescu had won 11 singles finals in the ITF Junior Circuit, losing only one set: Bucharest (Aug 2002), 6–1, 7–6 against Tsvetana Pironkova Cavtat]] (Apr 2003) 6–4, 6–1 against Darija Jurak Timişoara (Aug 2003) 6–2, 6–3 against Veronika Rizhik Albufeira (Feb 2004) 6–1, 3–6, 6–0 against Irina Kotkina Portimão (Feb 2004) 6–4, 7–6 against Nadja Pavić Bucharest (May 2004) 6–2, 6–2 against Simona Matei Iași (Aug 2004) 7–6, 6–0 against Raluca Olaru Cairo (Mar 2005) 6–4, 6–2 against Galina Fokina Ain Alsoukhna (Mar 2005) 6–3, 6–4 against Magdaléna Rybáriková Antalya (May 2005) 6–2, 6–2 against Ekaterina Dzehalevich Coimbra (Aug 2005) 6–3, 6–1 against Aravane Rezaï. She also won eight out of fourteen doubles events, most of them paired with her sister, Gabriela Niculescu. She reached the finals in girls' doubles at the French Open in 2004, paired with Mădălina Gojnea, and twice in Wimbledon in 2004 and 2005, paired with Marina Erakovic.

Professional 2007–08: First WTA doubles final, top 50 in the world

Niculescu had her first WTA Tour debuting attempt in May 2006 at the Istanbul Cup but lost in qualifying. In February of the following year, she made her WTA Tour main-draw debut at the Dubai Tennis Championships. In June 2007, she played her first doubles event at the Barcelona Open. There, she also recorded her first win in doubles at the WTA Tour. A month later, she managed to get to her first WTA event semifinal, at the Gastein Ladies in the doubles event. During the year, she also attempted to make her major debut but lost in the qualifyings of all four. She finished the year 2007 in the top 200.

In 2008 at the Australian Open, she played her first Grand Slam main draw as a qualifier. A month later, at the Qatar Open, she made her Tier I debut and also recorded her first win on the WTA Tour in a singles event. She continued making debuts at the French Open, Wimbledon and US Open, at Tier I events such as the Italian Open and Canadian Open. In doubles events, she managed to get to her first WTA final at the Connecticut Open alongside compatriot Sorana Cîrstea, but they failed to win the trophy. Niculescu finished the year inside the top 50 in both singles and doubles. In singles, she was ranked world No. 48, and second in Romania, at the end of 2008.

2009: First WTA Tour doubles title

Despite progress in previous seasons, the opening of the season was not promising for Niculescu. In May 2009, she reached her first singles quarterfinal at the Internationaux de Strasbourg. In the quarterfinal match, she lost to Aravane Rezaï. In her next quarterfinal appearance four months later, at the Tashkent Open, she advanced to the quarterfinal, then lost to Yaroslava Shvedova. Niculescu fell outside the top 100 at the end of the year, ranked 103.

In doubles, in February alongside Cîrstea, she reached semifinals of the Premier Open GdF Suez but then withdrew. She reached two back-to-back Premier 5/Mandatory quarterfinals at the Dubai Tennis Championships and the Indian Wells Open. Niculescu then had two consecutive Grand Slam third rounds - French Open and Wimbledon. She then won a WTA Tour doubles title, at the Budapest Grand Prix, winning alongside Alisa Kleybanova. Three weeks later, she advanced to another final at the Stanford Classic but failed to win. Soon after, she reached her first Premier 5/Premier Mandatory semifinal at the Cincinnati Open alongside Akgul Amanmuradova. By the end of the year, she reached the third round of the US Open and semifinals of the International-level Tashkent Open and Premier-level Kremlin Cup. She finished 2009 as world No. 30.

2010: First major QF in doubles

In late September, when she reached the semifinals at the Tashkent Open. She beat fellow Romanian and top-30 player, Alexandra Dulgheru, then lost her semifinal match to Elena Vesnina. During the year, she recorded only one major match win at Wimbledon, defeating Gisela Dulko in the first round. At the Premier 5/Premier Mandatory-level, she also scored only one win. It came at the Cincinnati Open, where she defeated Sabine Lisicki. Niculescu returned to the top 100 in August and stayed there for the rest of the season.

Niculescu reached the final of the Hobart International. At the French Open, she reached her first career Grand Slam quarterfinal. In July, she played another final at the Prague Open but finished runner-up. The following week, she won the title at the $100K Pétange tournament. Niculescu advanced to the quarterfinals of the Canadian Open, followed by a semifinal at the Cincinnati Open and a third round at the US Open.

2011: Singles breakthrough, top 30

At the Australian Open, Niculescu advanced to her first Grand Slam third round in singles. In the first round, she defeated top-50 player, Timea Bacsinszky, in straight sets. She then played against Tsvetana Pironkova, the 32nd seed; Niculescu lost five games. In the third round, she lost to the Grand Slam champion and top 10 Francesca Schiavone. In April, she reached her first semifinal of the year at the Estoril Open. She lost her semifinal match to Anabel Medina Garrigues.

At the 2011 US Open, after making three wins, she reached a Grand Slam round of 16 for the first time. Niculescu defeated Patricia Mayr-Achleitner in straight sets in the first round; in the second, top 50 Dulgheru won three games; and in the third round, she lost one game to top 30 Lucie Šafářová. She failed to reach her first singles Grand Slam quarterfinal after losing to Angelique Kerber in the straight-sets.

At the China Open, she first defeated top-10 player Li Na. She then defeated top 50 Chanelle Scheepers, losing three games. In both the third round and the quarterfinal, she made a turnover after losing the first set. In the semifinal, she faced No. 11 Andrea Petkovic but won only two games. Niculescu then finished the year with another WTA final, at the Luxembourg Open, but finished as a runner-up. In the final, she lost to No. 3 Victoria Azarenka. Right after that, she made her debut inside the top 30, finishing the year as No. 30 and No. 1 Romanian player.

She reached the semifinal of the Brisbane International in the first week of the year. Niculescu got to another semifinal in early April at the Andalucia Tennis Experience. Her best Grand Slam result of the year was the third round of the French Open. She reached only one WTA final, at the Baku Cup in July 2011.

2012–14: First WTA Tour singles title, second doubles major QF Singles

In February 2012, she reached the quarterfinal of the Qatar Open in singles event. In the second-round she defeated top 10 Vera Zvonareva. It was the second career top-10 win for Niculescu. Until October 2012, she was losing in the early round at all tournaments. She then jumped to the final of the Luxembourg Open for the second year in a row after making four consecutive straight-sets wins. She still did not win her first WTA singles title, losing to Venus Williams in the final match. The next two weeks, she played at the ITF Circuit as her last two singles tournaments of the year. First week, she reached the semifinal of the $100k Poitiers tournament, followed with the title at the $50k+H Open Nantes. In the final, she defeated Yulia Putintseva.

Niculescu started the 2013 season with the semifinal of the Shenzhen Open. Right after that, she came to Australia to play at the Hobart International, where she advanced to the quarterfinals. In early March, she won her first WTA singles title at the Brasil Tennis Cup in Florianópolis, after defeating Olga Puchkova in the final. A month later, she got to another semifinal at the Monterrey Open. By the end of the year, she reached one WTA Tour quarterfinal at the Washington Open. In 2013, she suffered first-round losses in all Grand Slam tournaments.

Niculescu started the year with two back-to-back quarterfinals of the Shenzhen Open and Hobart International. At the Australian Open, she reached the third round, after defeating No. 15 Lisicki in the three sets. It was first singles Grand Slam win for Niculescu, after making 7 consecutive Grand Slam first round losses. In July, she reached the semifinal of the Bucharest Open but lost to her compatriot and No. 3 Simona Halep. In September, she won her second career singles title at the Guangzhou Open. Niculescu won all matches in straight sets, defeating No. 22 Alizé Cornet in the final.

Doubles

In January 2012 she achieved a winning title at the Hobart International. The following week, she reached her second career Grand Slam quarterfinal in doubles at the Australian Open. In March 2012, she reached the semifinal of the Premier Mandatory Miami Open. It was her first at least quarterfinal of the Premier 5/Premier Mandatory tournaments after winning semifinal at the 2010 Canadian Open. In September 2012, she got to the final of the Guangzhou Open but finished runner-up. A month later, she finished again runner-up, this time at the Luxembourg Open.

In the first half of the 2013, she finished as a quarterfinalist at the Italian Open. She achieved at least one quarterfinal on both surfaces (hardcourt and clay) at the Premier 5/Premier Mandatory tournaments. It was also her eighth Premier 5/Premier Mandatory at least quarterfinal. In June, she reached the final of the Eastbourne International. Despite losing in the final match, she had accomplished at least one final on all three surfaces (hard, clay and grass).

Niculescu started the 2014 season with two back-to-back titles at the Shenzhen Open and Hobart International. At the Qatar Open, she reached her ninth Premier 5/Premier Mandatory quarterfinal. In April, she advanced to another WTA final at the Katowice Open but failed to win the trophy. During the year, she also reached two Premier semifinals, at the Open GdF Suez in late January and at the Connecticut Open in August.

2015: First Premier 5 final in doubles