Joanna Sakowicz-Kostecka (born 1 May 1984) is a former tennis player from Poland.

As a professional, her career-high singles ranking is world No. 138, achieved on 9 October 2006. Her highest doubles ranking is world No. 312, achieved on 23 June 2003.

In her career, she won three singles titles and one doubles title on the ITF Women's Circuit.

ITF finals $25,000 tournaments$10,000 tournaments

Singles (3–4) ResultNo.DateTournamentSurfaceOpponentScoreWin 1. 3 June 2001 Warsaw, Poland Clay Raluca Ciochină 1–6, 6–2, 6–1Loss 1. 18 November 2001 Stupava, Slovakia Hard (i) Petra Cetkovská 1–6, 4–6Win 2. 30 June 2002 Rabat, Morocco Clay Olga Kalyuzhnaya 6–3, 7–5Loss 2. 10 July 2005 Bella Cup, Poland Clay Ana Timotić 1–6, 2–6Loss 3. 27 November 2005 Opole, Poland Carpet Oxana Lyubtsova 1–6, 6–3, 1–6Win 3. 10 December 2005 Zubr Cup, Czech Republic Carpet (i) Lucie Hradecká 6–4, 6–4Loss 4. 11 July 2006 Bella Cup, Poland Clay Andreja Klepač 0–6, 2–6

Doubles (1–1) ResultNo.DateTournamentSurfacePartnerOpponentsScoreWin 1. 23 June 2002 Tallinn, Estonia Clay Petra Cetkovská Petra Rüssegger Stefanie Weis 6–2, 4–6, 6–4Loss 1. 5 July 2005 Bella Cup Toruń, Poland Clay Zuzana Hejdová Nadejda Ostrovskaya Yevgenia Savransky 1–6, 5–7

References