Djokovic appeared on the juniorITF circuit in September 2006. In July 2007, he failed to qualify for theCroatia Open Umag, losing toPablo Andújar 6–2, 6–1 in the 1st round of qualifying.[2] He also played, with his elder brother Novak, one doubles match in his career, having been beaten byÉdouard Roger-Vasselin andMathieu Montcourt 7–5, 6–1. Djokovic also has lost in twoFutures tournaments inNovi Sad in the first round, both times to compatriot Saša Stojisavljević. He contested theAustralian Open juniors in 2008, losing in the first round to Clifford Marsland in 3 sets. Djokovic won his first junior title at the Montenegro Open inPodgorica, defeating Ljubomir Čelebić in the final.[3] In July 2008, Djokovic received a wildcard entry into the qualifying rounds of the Croatia Open Umag but was beaten by ItalianFrancesco Piccari.[4] In September 2008, in his first ever main ATP Tour event, he received a wildcard entry into the main draw of theThailand Open.[5] He was defeated in the first round byJarkko Nieminen 6–2, 6–0. On 7 May 2009, Djokovic, withDarko Mađarovski (as a wildcard pair), defeated ATP doubles world number 2 duoDaniel Nestor andNenad Zimonjić, by 7–6, 2–6, [10–6], in the opening round of theSerbia Open, an ATP World Tour 250 tournament. This was Marko's first ever ATP win. He was included as a fifth player in the Serbian Davis Cup team for their quarterfinal tie against Croatia in the 2010 Davis Cup[6] – a standard practice ofTennis Federation of Serbia and Davis Cup captain Bogdan Obradović for each tie to invite a different talented young player to practice with regular players and gain necessary experience.[7] Djokovic was given a wildcard for the2012 Dubai Duty Free tournament and opened the ATP World Tour 500 event againstAndrei Golubev of Kazakhstan, losing in straight sets.[8] According to his elder brother Novak, he had stopped playing tennis in 2015,[9] but Marko has since played again in qualifying competitions on theATP Challenger Tour since 2017, successfully surpassing this phase in the2018 Copa Sevilla. The change in the ATP ranking points to start the 2019 season propelled Djokovic to a career-high ranking of world No. 574.[10]