The victory of Joko Widodo (‘Jokowi’) in Jakarta’s 2012 gubernatorial election has been described as a “triumph of democracy” as Joko and his running mate Basuki Tjahaja Purnama (‘Ahok’), a Chinese Christian, successfully won the election despite negative ethno-religious campaigns against them. How exactly did the ethno-religious boundary influence the election? By analysing the results of the election in relation to ethnicities and religions using the 2000 National Census, the author reveals an ethno-political map of Jakarta, for political analysis a potentially important but still under-researched area. The article then proceeds to examine the ‘religionisation’ process of the election campaign. The incumbent governor, Fauzi Bowo, carefully established his religious image and tried to mobilise support through religious symbols and persuasion, even though the electoral results seemed to be divided along ethnic lines. Joko also participated in a number of religious campaigns, albeit in a different way that was more subtle. Because ideological differences between Islamic and secular nationalist parties have become blurred and the general ‘religionisation’ of Indonesian society has continued, religious campaigns are becoming more important in domestic politics, even for ‘less-Islamic’ politicians like Joko.