International expert:

In elections on both sides of the Atlantic, that are likely to have deep implications for their respective regions, one incumbent won, another lost. In Brazil, Latin America's biggest country, left-wing President Lula won a fourth term in office, defeating his right-wing challenger Flávio Bolsonaro. The 80-year-old, took just under 52% of the vote in a run-off on Sunday. Lula thanked cheering supporters in São Paulo and said he had defended Brazil's democracy. His opponent, Flavio Bolsonaro - who won the first round - says the result is "inexplicable" and called for it to be annulled. His father, ex-president Jair Bolsonaro, is currently serving a jail sentence under house arrest for plotting a coup after losing the last election. This election was bitterly fought - and it bucks a wider regional trend towards right-wing leaders. On the other side of the Atlantic, in Serbia, long-standing leader Aleksandar Vučić has admitted defeat to the student-led protest movement in snap parliamentary elections. "We still do not have final results... it is clear that we have lost these elections," the right-wing populist leader said as he conceded late on Sunday. Preliminary figures from Serbia's election commission indicated a record high turnout, which commentators had suggested would favour the student movement. Celebrations erupted after Vučić conceded. Vučić called the snap elections after two years of protests triggered by the collapse of a train station canopy in the city of Novi Sad, which killed 16 and was seen as emblematic of corruption and negligence. Both election results are going to have a deep impact on their respective regions.