2009: Grand Slam debut

Diatchenko's first Grand Slam tournament was Roland Garros, where she 2009 qualified for the main draw. In the tournament, she upset world No. 75 player, Mathilde Johansson, before she lost to then-world No. 1, Dinara Safina.

In 2009, she lost the finals of Pattaya Open along with Yulia Beygelzimer to opponents Tamarine Tanasugarn and Yaroslava Shvedova, in straight sets, and of Tashkent Open with Ekaterina Dzehalevich to Tatiana Poutchek and Olga Govortsova, in three sets.

2010

In 2010, she lost the final of the Portugal Open with Aurélie Védy to opponents Anabel Medina Garrigues and Sorana Cîrstea.

At the French Open, she was beaten in the third round of qualifying by Misaki Doi.^[2] At the Wimbledon Championships qualifying, she lost in the second round to Monica Niculescu in two sets. Diatchenko also participated in events on the ITF Circuit: she won the tournament in Darmstadt, Germany; in the final, she beat eighth seeded German player Julia Schruff.

Then she lost her fourth WTA International doubles final with partner Tatiana Poutchek, at Copenhagen to German pair Anna-Lena Grönefeld/Julia Görges.

2011: Top 60 debut in doubles, injury and hiatus

Diatchenko at the 2011 US Open

Vitalia lost in the qualifying at Melbourne in the second round to Sania Mirza in three sets. She then entered the qualifying at Dubai but lost in the first round to Anastasia Pavlyuchenkova, after being 3–1 ahead in the second set.

Diatchenko qualified for the Wimbledon Championships for the first time in her career by defeating Julia Glushko, Maria Elena Camerin and Stéphanie Dubois for her first main draw in a Grand Slam tournament. In the first round, she was defeated by 25th seed Daniela Hantuchová in three sets. Vitalia was also defeated in the first round of the women's doubles with compatriot Maria Kondratieva, by Vera Dushevina and Ekaterina Makarova.

Seeded first at the GB Pro-Series Foxhills, she defeated fifth seed Marta Sirotkina in the quarterfinals. In her semifinal match, she retired whilst trailing 2–6, 0–2 to Johanna Konta.

On July 30, Diatchenko won the biggest singles title of her career so far at the President's Cup, an $100k tournament held in Astana. She beat sixth seed Akgul Amanmuradova in the final. She also won the women's doubles title with Galina Voskoboeva. They defeated Amanmuradova and Alexandra Panova in the final, also in two sets.

Vitalia participated in the Tatarstan Open in singles and doubles. Alexandra Panova was her doubles partner. Diatchenko was seeded fifth in the singles and first in the doubles. In the first round of the singles, she defeated Eugeniya Pashkova, in the second round Pemra Özgen, and in the quarterfinals Valentyna Ivakhnenko, all in straight sets. In the semifinals, Vitalia retired against wildcard and eventual champion, Yulia Putintseva, after suffering an ankle injury. In the doubles, after winning their first round and quarterfinal matches, Vitalia and Alexandra upset third seeds Evgeniya Rodina and Valeria Solovyeva in the semifinals. Due to suffering an injury in the semifinals of the singles, Vitalia was unable to play the doubles final.

At the US Open, she beat Laura Siegemund in the first round of the qualifying stages, Sesil Karatantcheva also in two sets, and in the final round Marta Domachowska in three for a place in the main draw. It was the first time she qualified for the main draw of the US Open. In the first round, she was defeated by Zheng Jie.

In the Tashkent Open, she fought past Olga Govortsova in three sets before she lost to Alla Kudryavtseva in the second round.^[3] In the doubles, Vitalia and her partner Eleni Daniilidou beat Lyudmyla Kichenok and Nadiya Kichenok in the final, in straight sets. This was Vitalia's first time to win a WTA Tour doubles title in her career.

She qualified for the Ladies Linz but lost in the first round to Ksenia Pervak.

Playing doubles at the Kremlin Cup, Vitalia suffered a knee injury which ruled her out from playing tennis for six months.

2014: First WTA 125 title and career-high singles ranking

After a brief appearance on the WTA Tour and a return to the ITF Circuit, she played her first notable game for years at the Kremlin Cup, where the 140-ranked Vitalia eliminated No. 14, Dominika Cibulková, in the round of 16, until being knocked down by Anastasia Pavlyuchenkova. Diatchenko completed the year by winning her first WTA 125 singles title at Taipei.

2018: Wimbledon 3rd round

In the first round of Wimbledon, she defeated former world No. 1, Maria Sharapova (ranked 22nd at the time).^[4] Diatchenko then defeated Sofia Kenin, advancing to the third round of a major tournament for the first time but Jeļena Ostapenko defeated her in straight sets.^[5]

2023

In April 2023, LOT Polish Airlines refused to board Diatchenko on a flight from Egypt to Corsica via Warsaw to play at a tournament, in line with travel restrictions for Russian passport holders introduced after the Russian invasion of Ukraine.^[6] Diatchenko confirmed that she was unable to reach her destination and then returned to Moscow.^[6]

Singles

Current after the 2023 Australian Open.

Doubles

Doubles: 7 (1 title, 6 runner-ups)

Result	W–L	Date	Tournament	Tier	Surface	Partner	Opponents	Score
Loss	0–1	Feb 2009	Pattaya Open, Thailand	International[lower-alpha 3]	Hard	Yuliya Beygelzimer	Tamarine Tanasugarn Yaroslava Shvedova	3–6, 2–6
Loss	0–2	Sep 2009	Tashkent Open, Uzbekistan	International	Hard	Ekaterina Dzehalevich	Tatiana Poutchek Olga Govortsova	2–6, 7–6(1), [8–10]
Loss	0–3	May 2010	Estoril Open, Portugal	International	Clay	Aurélie Védy	Anabel Medina Garrigues Sorana Cîrstea	1–6, 5–7
Loss	0–4	Aug 2010	Kopenhagen Open, Denmark	International	Hard (i)	Tatiana Poutchek	Julia Görges Anna-Lena Grönefeld	4–6, 4–6
Win	1–4	Sep 2011	Tashkent Open, Uzbekistan	International	Hard	Eleni Daniilidou	Lyudmyla Kichenok Nadiya Kichenok	6–4, 6–3
Loss	1–5	Jan 2015	Hobart International, Australia	International	Hard	Monica Niculescu	Kiki Bertens Johanna Larsson	5–7, 3–6
Loss	1–6	Aug 2015	Baku Cup, Azerbaijan	International	Hard	Olga Savchuk	Margarita Gasparyan Alexandra Panova	3–6, 5–7

Singles: 3 (3 titles)

Result	W–L	Date	Tournament	Surface	Opponent	Score
Win	1–0	Nov 2014	Taipei Challenger, Taiwan	Carpet (i)	Chan Yung-jan	1–6, 6–2, 6–4
Win	2–0	Nov 2019	Taipei Challenger, Taiwan (2)	Carpet (i)	Tímea Babos	6–3, 6–2
Win	3–0	Dec 2021	Open Angers, France	Hard (i)	Zhang Shuai	6–0, 6–4

Doubles: 1 (runner-up)

Result	W–L	Date	Tournament	Surface	Partner	Opponents	Score
Loss	0–1	Jun 2022	Veneto Open, Italy	Grass	Oksana Kalashnikova	Madison Brengle Claire Liu	4–6, 3–6

Singles: 28 (21 titles, 7 runner–ups)

Result	W–L	Date	Tournament	Tier	Surface	Opponent	Score
Win	1–0	Nov 2007	ITF Redbridge, United Kingdom	10,000	Hard (i)	Iveta Gerlová	6–4, 6–0
Win	2–0	Dec 2008	Dubai Challenge, UAE	75,000	Hard	Urszula Radwańska	7–5, 2–6, 7–5
Win	3–0	Mar 2009	ITF Moscow, Russia	25,000	Hard (i)	Vesna Manasieva	2–6, 6–3, 4–1 ret.
Win	4–0	Jul 2010	ITF Darmstadt, Germany	25,000	Clay	Julia Schruff	6–4, 5–7, 6–4
Loss	4–1	Aug 2010	Tatarstan Open, Russia	50,000	Hard	Anna Lapushchenkova	1–6, 6–2, 6–7(4)
Win	5–1	Jul 2011	President's Cup, Kazakhstan	100,000	Hard	Akgul Amanmuradova	6–4, 6–1
Win	6–1	Dec 2013	Ankara Cup, Turkey	50,000	Hard (i)	Marta Sirotkina	6–7(3), 6–4, 6–4
Win	7–1	Mar 2014	ITF Sharm El Sheikh, Egypt	10,000	Hard	Naomi Broady	3–6, 6–4, 6–1
Loss	7–2	Mar 2014	ITF Sharm El Sheikh, Egypt	10,000	Hard	Naomi Broady	2–6, 0–3 ret.
Loss	7–3	May 2014	ITF Moscow, Russia	25,000	Clay	Anastasiya Vasylyeva	5–7, 4–6
Win	8–3	Jul 2014	President's Cup, Kazakhstan (2)	100,000	Hard	Çağla Büyükakçay	6–4, 3–6, 6–2
Win	9–3	Sep 2014	ITF Moscow, Russia (2)	25,000	Clay	Evgeniya Rodina	6–3, 6–1
Loss	9–4	Sep 2014	Royal Cup, Montenegro	25,000	Clay	Andreea Mitu	1–6, 4–6
Win	10–4	Jun 2015	Surbiton Trophy, United Kingdom	50,000	Grass	Naomi Osaka	7–6(5), 6–0
Loss	10–5	Dec 2016	Ankara Cup, Turkey	50,000	Hard (i)	Ivana Jorović	4–6, 5–7
Win	11–5	Aug 2017	ITF Chiswick, United Kingdom	25,000	Hard	Viktória Kužmová	6–3, 6–4
Win	12–5	Oct 2017	ITF Istanbul, Turkey	25,000	Hard (i)	Jaqueline Cristian	6–3, 6–1
Win	13–5	Aug 2018	ITF Chiswick, United Kingdom (2)	25,000	Hard	Valentini Grammatikopoulou	6–1, 7–5
Win	14–5	Feb 2019	Open de l'Isère, France	25,000	Hard (i)	Harmony Tan	6–1, 6–4
Win	15–5	Feb 2019	GB Pro-Series Shrewsbury, UK	60,000	Hard (i)	Yanina Wickmayer	5–7, 6–1, 6–4
Win	16–5	Mar 2019	Open de Seine-et-Marne, France	60,000	Hard (i)	Robin Anderson	6–2, 6–3
Win	17–5	Apr 2019	ITF Bolton, United Kingdom	25,000	Hard (i)	Jodie Anna Burrage	6–2, 6–2
Win	18–5	Apr 2019	Lale Cup Istanbul, Turkey	60,000	Hard	Ankita Raina	6–4, 6–0
Win	19–5	Sep 2019	ITF Penza, Russia	25,000+H	Hard	Kamilla Rakhimova	6–4, 6–1
Win	20–5	Feb 2022	ITF Macon, France	25,000	Hard (i)	Cristiana Ferrando	6–4, 6–3
Loss	20–6	Jun 2022	ITF Cantanhede, Portugal	25,000	Carpet	Francisca Jorge	5–7, 5–7
Win	21–6	Jun 2022	ITF Santarem, Portugal	25,000	Hard	Isabella Kruger	6–3, 6–2
Loss	21–7	May 2023	ITF Tbilisi, Georgia	40,000	Hard	Stacey Fung	4–6, 0–0 ret.

Doubles: 18 (13 titles, 5 runner–ups)

Result	W–L	Date	Tournament	Tier	Surface	Partner	Opponents	Score
Loss	0–1	Jun 2007	ITF Sarajevo, BiH	10,000	Clay	Tamara Stojković	Vasilisa Davydova Karolina Jovanović	6–1, 0–6, 0–6
Win	1–1	Aug 2008	ITF Moscow, Russia	75,000	Clay	Maria Kondratieva	Veronika Kapshay Irina Kuzmina	6–0, 6–4
Win	2–1	Aug 2008	ITF Moscow, Russia	25,000	Clay	Eugeniya Pashkova	Tadeja Majerič Natalia Ryzhonkova	6–0, 6–1
Loss	2–2	Sep 2008	ITF Ruse, Bulgaria	25,000	Clay	Eugeniya Pashkova	Alexandra Panova Ksenia Pervak	2–6, 7–6(5), [5–10]
Loss	2–3	Mar 2009	ITF Minsk, Belarus	25,000	Carpet	Eugeniya Pashkova	Ima Bohush Darya Kustova	1–6, 6–4, [8–10]
Win	3–3	Mar 2009	ITF Moscow, Russia	25,000	Hard	Ekaterina Dzehalevich	Lyudmyla Kichenok Nadiya Kichenok	6–1, 6–1
Loss	3–4	Mar 2010	ITF Minsk, Belarus	25,000	Hard	Maret Ani	Elena Bovina Irena Pavlovic	0–6, 1–6
Win	4–4	Apr 2010	Soweto Open, South Africa	100,000	Hard	Irini Georgatou	Marina Erakovic Tamarine Tanasugarn	6–3, 5–7, [16–14]
Win	5–4	Jul 2010	ITF Darmstadt, Germany	25,000	Clay	Laura Siegemund	Irina-Camelia Begu Erika Sema	4–6, 6–1, [10–4]
Win	6–4	Sep 2010	GB Pro-Series Shrewsbury, UK	75,000	Hard	Irena Pavlovic	Claire Feuerstein Vesna Manasieva	4–6, 6–4, [10–6]
Win	7–4	Oct 2010	ITF Athens Open, Greece	50,000	Hard	İpek Şenoğlu	Eleni Daniilidou Petra Martić	w/o
Win	8–4	Jul 2011	President's Cup, Kazakhstan	100,000	Hard	Galina Voskoboeva	Akgul Amanmuradova Alexandra Panova	6–3, 6–4
Loss	8–5	Aug 2011	Tatarstan Open, Russia	50,000	Hard	Alexandra Panova	Ekaterina Lopes Andreja Klepač	w/o
Win	9–5	Nov 2013	Dubai Tennis Challenge, UAE	75,000	Hard	Olga Savchuk	Lyudmyla Kichenok Nadiya Kichenok	7–5, 6–1
Win	10–5	Jul 2014	President's Cup, Kazakhstan	100,000	Hard	Margarita Gasparyan	Michaela Boëv Anna-Lena Friedsam	6–4, 6–1
Win	11–5	Aug 2014	Neva Cup, Russia	25,000	Clay	Ilona Kremen	Natela Dzalamidze Anastasia Pivovarova	6–1, 6–3
Win	12–5	Nov 2014	Dubai Tennis Challenge, UAE	75,000	Hard	Alexandra Panova	Lyudmyla Kichenok Olga Savchuk	3–6, 6–2, [10–4]
Win	13–5	May 2016	ITF La Marsa, Tunisia	25,000	Clay	Galina Voskoboeva	Victoria Kan Sabina Sharipova	6–3, 1–6, [12–10]