The ATP Challenger Tour, known until the end of 2008 as the ATP Challenger Series, is a series of international men's professional tennis tournaments. It was founded in 1976 when it replaced the ILTF Satellite Circuit as the second tier of tennis. The Challenger Tour events are the second-highest tier of tennis competition, behind the ATP Tour. The ITF World Tennis Tour tournaments are on the entry-level of international professional tennis competition. The ATP Challenger Tour is administered by the Association of Tennis Professionals. Players who succeed on the ATP Challenger Tour earn sufficient ranking points to become eligible for main draw or qualifying draw entry at ATP Tour tournaments. Players on the Challenger Tour are usually young players looking to advance their careers, those who fail to qualify for ATP events, or former ATP players looking to get back into the big tour.
Daniel Dutra da Silva is a Brazilian professional tennis player. He competes mostly on the ATP Challenger Tour.
Alessandro Giannessi is a professional Italian tennis player. On 24 July 2017 he reached his highest ATP singles ranking of world No. 84 while his best doubles ranking was No. 171 on 14 October 2013.
Viktor Durasovic is a Norwegian professional tennis player.
Geoffrey Blancaneaux is a French professional tennis player who competes mainly on the ATP Challenger Tour. He has a career-high ATP singles ranking of World No. 134 achieved on 14 November 2022 and a doubles ranking of World No. 164 achieved on 18 July 2022.
The Marbella Tennis Open is a professional tennis tournament played on clay courts. It is currently part of the Association of Tennis Professionals (ATP) Challenger Tour and WTA 125K series. The ATP event has been held annually in Marbella, Spain, from 2018 while the WTA edition started in 2022.
The Bratislava Open is a professional tennis tournament played on clay courts.
Juan Pablo Ficovich is an Argentine professional tennis player.
Zizou Bergs is a Belgian professional tennis player. He has a career high ATP singles ranking of No. 61 achieved on 4 November 2024 and a best doubles ranking of No. 265 achieved on 27 November 2023. He is currently the No. 2 Belgian singles player.
Lukáš Klein is a Slovak professional tennis player. Klein has a career-high ATP singles ranking of world No. 109, achieved on 5 August 2024. He also has a career-high doubles ranking of No. 240, achieved on 5 April 2021. He is currently the No. 2 Slovak tennis player in singles.
Camilo Ugo Carabelli is an Argentine professional tennis player, who competes mainly on the ATP Challenger Tour. He has a career high ATP singles ranking of world No. 91 achieved on 5 August 2024 and a doubles ranking of No. 232 achieved on 21 March 2022. He has won six Challenger and four Futures singles titles.
Sergio Martos Gornés is a Spanish tennis player who specializes in doubles. He has a career high ATP doubles ranking of World No. 102 achieved on 12 June 2023. He also has a career high singles ranking of No. 726 achieved on 20 July 2015.
Riccardo Bonadio is an Italian former professional tennis player.
Oleksii Krutykh is a Ukrainian tennis player. He has a career high ATP singles ranking of World No. 160 achieved on 27 February 2023. He also has a career high doubles ranking of World No. 275 achieved on 5 December 2022. He has won two ATP Challenger singles titles and two doubles titles. He is currently the No. 9 Ukrainian tennis player.
Santiago Rodríguez Taverna is an Argentine professional tennis player. He has a career high ATP singles ranking of world No. 157 achieved on 29 August 2022. He also has a career high doubles ranking of No. 160 achieved on 20 November 2022.
The Sparta Prague Open Challenger is a professional tennis tournament played on clay courts. It is currently part of the Association of Tennis Professionals (ATP) Challenger Tour. It has been held in Prague, Czech Republic since 2000 at TK Sparta Prague, founded in 1905 near Stromovka, inside Prague's Bubeneč district.
The 2022 Saturn Oil Open was a professional tennis tournament that was played on clay courts. It was the first edition of the tournament which was part of the 2022 ATP Challenger Tour. It took place in Troisdorf, Germany between 23 and 29 May 2022.
Jelle Sels is a Dutch tennis player. Sels competes mainly in the Challenger tour circuit. He has a career high ATP singles ranking of world No. 127 achieved on 28 November 2022. He also has a career high doubles ranking of world No. 201 achieved on 20 June 2022.
The Vilnius Open, known as the Vilnius Open by kevin. for sponsorship reasons, is a professional tennis tournament, held in Vilnius, Lithuania, at the end of October since 2022. The tournament is held on indoor hard courts of the SEB Arena.
The 2023 Saturn Oil Open was a professional tennis tournament that was played on clay courts. It was the second edition of the tournament which was part of the 2023 ATP Challenger Tour. It took place in Troisdorf, Germany between 29 May and 4 June 2023.
2023 Saturn Oil Open 
