[3] Later in the year, Kližan won his first Challenger tournament as a wildcard in his hometown of Bratislava at the Slovak Open.
At the 2013 French Open, he lost in the second round against eventual champion Rafael Nadal, despite winning the first set.
Subsequently, he participated in a Challenger tournament in Caltanissetta, Italy, where Kližan suffered a shocking loss to non-ranked player Pablo Carreño Busta in the first round.
He did not play for six weeks due to a wrist injury and withdrew from St. Petersburg, where he was the defending champion.
Kližan started the year with a first-round loss at the Nouméa, New Caledonia Challenger tournament to World No.
After a poor start of the year, he found very good subsequent form at the Australian Open.
Starting from qualifying once more, Kližan surprisingly won the BMW Open, beating Mikhail Youzhny and Tommy Haas en route to the final, where he defeated top seeded Fabio Fognini.
Kližan won his third ATP doubles title at the Rio Open, partnering Philipp Oswald.
Originally, the Slovak nominations were announced without Kližan, but he later changed his decision and decided to partake in the tie.
[9] In April, Kližan won his third ATP title in Casablanca, defeating Daniel Gimeno Traver in the final.
[12] He subsequently won his fourth title in Rotterdam, beating Gaël Monfils in the final, coming back from a set down.
On his way to the title, Kližan saved eight match points (five against Roberto Bautista Agut and three against Nicolas Mahut).
[13] Kližan seized his second ATP 500 title at the 2016 German Open, defeating Pablo Cuevas in the final in straight sets.
Kližan qualified for the main draw of the 2017 Monte-Carlo Rolex Masters, but he lost to Nicolás Almagro in the first round, after receiving two game penalties for unsportsmanlike conduct in the third set.
[20] In Budapest, Kližan defeated two qualifiers: Maximilian Marterer and Bjorn Fratangelo, before losing to top seed and eventual winner Lucas Pouille in the quarterfinals.
[21] In Munich, Kližan defeated Nicolás Kicker and Mischa Zverev, before losing to Chung Hyeon in the quarterfinals.
[31] In Munich, Kližan qualified into the main draw and reached the quarterfinals, where he lost to Chung Hyeon.
[32] Kližan qualified for the main draw at Roland Garros, where he lost in the second round to Gaël Monfils.
Kližan did just that, defeating Denis Istomin in the final, top seed Dominic Thiem as well as Dušan Lajović in the quarterfinals, against whom he saved two match points.
[39] Martin Kližan's retirement to be announced after Wimbledon was reported on 2 June 2021, according to information published by the Slovakian Tennis Federation.
[41][42] Since his retirement, Kližan ran in the local elections for Mayor of Petržalka and applied for the position of president of the Slovak Tennis Association, both of which failed.
After a re-watch of the 2014 China Open quarterfinals win against Nadal, Kližan started having ideas about a comeback to professional tennis.
Ugo Humbert In January 2022, Martin Kližan faced criticism after publishing post on Instagram, in which he attacked the sexual orientation of former tennis player [Martina Navrátilová] because of her statement towards tennis player [Novak Đoković] regarding his refusal to be vaccinated.