Sorana Cirstea turned pro at 2006 Stockholm (l. Kanepi in 1r). Next year she reached her first WTA finalI in Budapest. As a qualifier in the Tier III event, she became the first Romanian player to reach a Tour final since Ruxandra Dragomir in June 2000 (l. to Dulko). Then she won her first WTA title in Tashkent beating Lisicki and finished the season at No. 36.
In 2009 she advanced to her first Grand Slam quarterfinal, at Roland Garros (l. to Stosur). After three top 100 season without playing a final, in 2012 Cirstea made her Top 30 debut as she reached four semifinals in Pattaya City (l. to Kirilenko), Barcelona (l. to Cibulkova), Stanford (l. to S.Williams) and Guangzhou (l. to Robson). She was R‐Up at 2013 Toronto (l. S.Williams), her maiden Premier 5 final, and clinched a career‐high ranking of No.21 (reached August 21, 2013). Next year, her seventh Top 100 season, she played three quarterfinals in Pattaya City (l. to Ka.Pliskova 16 76(3) 60; held 2mp at 61 54), Dubai and Tianjin. She struggled with a right shoulder injury in 2014 and 2015, when she finished at No.244.
Cirstea finished 2016 season at No.81 as she completed a semifinal run in Rio de Janeiro (l. Rogers) and made quarterfinals at Premier Mandatory Madrid (as wildcard, l. eventual R‐Up Cibulkova) and Mallorca (as qualifier, l. Jankovic).
At 2017 Australian Open, she achieved second‐best Slam result by reaching R16 (upset No.10 seed Suárez Navarro in 2r, l. Muguruza). Clay season highlighted by semifinal run in Nürnberg (l. Krejcikova) and quartefinal efforts at Istanbul (l. eventual champion Svitolina) and Madrid (l. Mladenovic). She finished the season at No.37, her highest year-end ranking since 2013.