Belgrade (dpa) - Serbian Prime Minster Aleksandar Vucic was heading toward a first-round triumph in presidential elections over the weekend, pollsters said Wednesday.A phone survey carried out by the Demostat agency on 1,200 voters from March 21 to 27 indicated Vucic winning 56.2 per cent of the ballots. For a win in the first round, on Sunday, he needs to win more than half of the votes cast.None of the candidates from the fragmented, bickering opposition was tipped to collect votes even in the double digits.In a potential additional blow to the opposition, the leading challenger is Luka Maksimovic, who runs under an alias and behind the mask of a mock character, Ljubisa Preletacevic Beli.Beli, who pokes fun at encrusted, corrupt Serbian politics, has 9.5 per cent, ahead of the former foreign minister and UN General Assembly president, Vuk Jeremic, with 9.3 per cent.Next in line are Serbia‘s former ombudsman Sasa Jankovic and the far right nationalist and Vucic‘s estranged political father, Vojislav Seselj, with just under 9 per cent of the votes.The remaining seven runners combined for 7.3 per cent in the Demostat survey.Vucic‘s support has remained effectively unchanged since a month before.The pollsters said that 18 per cent of those polled declared themselves as undecided. The agency predicted a turnout of 57 per cent.If Vucic wins, as predicted, he will sidestep from the formally far more powerful office of prime minister to that of president, but it is certain that he will retain his personal authority.