Marin Čilić was the two-time defending champion, but chose not to participate this year.
Damir Džumhur was the defending champion, but lost in the quarterfinals to Stan Wawrinka.
Roberto Bautista Agut was the defending champion, but lost in the second round to Nikoloz Basilashvili.
Nick Kyrgios defeated Daniil Medvedev in the final, 7–6(8–6), 7–6(7–4) to win the men's singles tennis title at the 2019 Washington Open. Kyrgios saved a match point in the semifinals against Stefanos Tsitsipas.
Daniil Medvedev defeated David Goffin in the final, 7–6(7–3), 6–4 to win the men's singles tennis title at the 2019 Cincinnati Masters. It was his first ATP Tour Masters 1000 title.
Dominic Thiem was the defending champion, but chose to compete in the Laver Cup instead.
Karen Khachanov was the defending champion, but lost in the quarterfinals to Andreas Seppi.
The 2020 St. Petersburg Open is a tennis tournament played on indoor hard courts that is part of the 2020 ATP Tour. It is the 25th edition of the St. Petersburg Open. The tournament was originally scheduled to take place from September 21 to 27, 2020, but was moved to October 12–18, and, since the ongoing COVID-19 pandemic caused many tournaments to be cancelled, upgraded to ATP 500 level for this one year. It is taking place at the Sibur Arena in Saint Petersburg, Russia.
Daniil Medvedev defeated Alexander Zverev in the final, 5–7, 6–4, 6–1 to win the singles tennis title at the 2020 Paris Masters.
Two-time defending champion Novak Djokovic defeated Daniil Medvedev in the final, 7–5, 6–2, 6–2 to win the men's singles tennis title at the 2021 Australian Open. It was his record-extending ninth Australian Open title and his 18th major title overall. With his fourth round win against Milos Raonic, Djokovic joined Roger Federer as only the second man with 300 or more match wins in majors.
Ugo Humbert defeated Andrey Rublev in the final 6–3, 7–6(7–4), to win the singles tennis title at the 2021 Halle Open. Humbert's win earned him his third career ATP Tour singles title and his first ATP 500 victory, and also made him the first French player to win the tournament since Henri Leconte won the inaugural edition in 1993. Both Humbert and Rublev were contesting their first career final on grass.
Alexander Zverev defeated Andrey Rublev in the final, 6–2, 6–3 to win the men's singles tennis title at the 2021 Cincinnati Masters. It was his fifth Masters 1000 title and 17th career singles title on the ATP Tour.
Andrey Rublev defeated Félix Auger-Aliassime in the final, 7–5, 7–6(7–4) to win the singles title at the 2022 Open 13 Provence.
Taylor Fritz defeated Rafael Nadal in the final, 6–3, 7–6(7–5) to win the men's singles title at the 2022 Indian Wells Masters. It was his first Masters 1000 title and second career title overall. Fritz became the first American to win the title since Andre Agassi in 2001, and ended Nadal's 20-match winning streak, dating back to the 2022 Melbourne Open.
Carlos Alcaraz defeated Casper Ruud in the final, 7–5, 6–4 to win the men's singles tennis title at the 2022 Miami Open. It was his first Masters 1000 title, and he became the first Spaniard to win the title. The victory also made Alcaraz, at 18 years and 333 days old, the youngest men's singles titlist in Miami Open history, and the youngest Masters 1000 champion since Rafael Nadal at the 2005 Monte Carlo Masters. Ruud became the first Norwegian to reach a Masters 1000 final, and the first Scandinavian since Robin Söderling at the 2010 Paris Masters.
Novak Djokovic defeated Stefanos Tsitsipas in the final, 6–0, 7–6(7–5) to win the men's singles tennis title at the 2022 Italian Open. It was his sixth Italian Open title and record-extending 38th Masters 1000 title overall. Djokovic did not lose a set during the tournament, and won his 1000th ATP Tour-level career match against Casper Ruud in the semifinals.
Borna Ćorić defeated Stefanos Tsitsipas in the final, 7–6(7–0), 6–2 to win the men's singles tennis title at the 2022 Cincinnati Masters. It was his first Masters 1000 title, and his first title overall since the 2018 Halle Open. Ranked No. 152 in the world and using a protected ranking for entry, Ćorić became the lowest ranked player to win a Masters event since the series' inception in 1990. He defeated five seeded players en route to the title.
Daniil Medvedev defeated the defending champion Andrey Rublev in the final, 6–2, 6–2 to win the men's singles tennis title at the 2023 Dubai Tennis Championships. It was Medvedev's third ATP Tour title in as many weeks, following championships in Rotterdam and Doha. He did not drop a single set en route to the title.
Daniil Medvedev defeated Jannik Sinner in the final, 7–5, 6–3 to win the men's singles tennis title at the 2023 Miami Open. It was his fifth career ATP Tour Masters 1000 title, fourth title of 2023, and 19th career title overall. He became only the eighth man to win a fifth Masters title.
Andrey Rublev defeated Holger Rune in the final, 5–7, 6–2, 7–5 to win the men's singles tennis title at the 2023 Monte-Carlo Masters. It was his first ATP Tour Masters 1000 title. 19-year-old Rune became the first teenager to reach the Monte-Carlo Masters final since Rafael Nadal in 2006.
Andrey Rublev 
Borna Ćorić 
