President Recep Tayyip Erdogan today celebrated winning five more years in office with sweeping new powers after a decisive election victory, as Turkey's opposition raised bitter questions over the conduct of the polls. A night of triumph for Erdogan saw the man who has dominated Turkey for the last one-and-a-half-decades declared winner of Sunday's presidential polls without needing a second round and lead his ruling party-led alliance to an overall majority in parliament. Erdogan, whose victory was wider than predicted by many analysts, immediately vowed to "rapidly" implement the new presidential system agreed in an April 2017 referendum that opponents fear will give him autocratic powers. The president, 64, declared victory in Istanbul before returning to Ankara to deliver a triumphant speech at 3:00 am to tens of thousands of supporters from the balcony of the headquarters of his Justice and Development Party (AKP). "Turkey has given a lesson in democracy to the entire world," he added, pointing to a turnout of 88 percent. His main rival Muharrem Ince of the Republican People's Party (CHP), who had challenged Erdogan with an energetic campaign and earlier accused the authorities of "manipulation", maintained an unusual silence after the results were announced but was due to make a statement later Monday. His party bitterly complained over the publication of the election results, accusing the state-run news agency Anadolu of publishing results favourable to Erdogan early on to give the impression of an easy victory. "Victory in the first round," trumpeted the headline in the Hurriyet daily. But the pro-opposition BirGun took a different line: "An unfair election," it said, adding that the way results had been delivered had given rise to "doubts". According to Anadolu's results, Erdogan won 52.5 percent of the vote in the presidential polls, with Ince trailing on 30.7. Final results are due to be published by the Supreme Election Board (YSK) later this week but its chairman Sadi Guven declared Erdogan the winner. If confirmed, the results will mean Erdogan, who still enjoys sky-high support in parts of the Anatolian heart of the country, even improved on his score from 2014 presidential elections of 51.8 percent. The candidate of the pro-Kurdish Peoples' Democratic Party Selahattin Demirtas came third on 8.4 percent, a position all the more remarkable given he has been jailed on charges of links to Kurdish militants since November 2016. Nationalist politician Meral Aksener, tipped for a breakthrough after founding her new Iyi (Good) Party, suffered a disappointing night coming fourth on 7.3 percent. With Turkey holding parliamentary and presidential elections on the same day for the first time, Erdogan was also able to enjoy an overall majority in parliament with the help of his allies from the right-wing Nationalist Movement Party (MHP). The AKP won 293 seats in the 600 MP chamber but the MHP did far better than expected, winning 50 seats and giving their alliance a clear majority, according to the results published by Anadolu. There was good news for the HDP which easily broke through the 10 percent minimum vote threshold to pick up up 67 seats, sparking wild celebrations in its Kurdish-majority stronghold of Diyarbakir. Congratulations for Erdogan flooded in from Turkey's partners in the Islamic world and allies who also have tetchy relations with the West, such as Russian President Vladimir Putin who praised Erdogan's "great political authority", the Kremlin said. Others congratulating Erdogan included Iranian President Hassan Rouhani, Venezuelan President Nicolas Maduro and Sudan's President Omar al-Bashir but there was no word yet from big EU states or the US. The European Union and United States were keeping a close eye on the poll and trans-Atlantic security body the OSCE was due to deliver its verdict on the election later in the afternoon. Erdogan has transformed Turkey first as prime minister from 2003 to 2014 and then as president, allowing Islam a greater role in public life and giving the country a much more assertive profile on the international stage. But critics accuse him of ruling with an iron grip, especially after the July 2016 failed coup which was followed by a state of emergency that has seen tens of thousands arrested. He now has a new five-year mandate and, although the president in Turkey can serve only two terms, this will count as Erdogan's first term under the new constitution. Consequently, he could now stay in power until 2028. The outcome relieved investors who had feared a prolonged period of uncertainty if the election went to a second round, with the Turkish lira gaining three percent in value against the dollar.