Turkey's main opposition party has taken the lead in some of the country's biggest cities, including Istanbul, in high-stakes local elections.
Opposition mayor Ekrem İmamoğlu, who won Istanbul in 2019, said he was “very satisfied” so far.
A year after Recep Tayyip Erdogan won a third term as president, he became mayor with the goal of reclaiming the city he grew up in.
Secular nationalist opposition is also gaining ground in the capital, Ankara.
Mansour Yavas also won the city from Erdogan's AK Party five years ago.
Both Yavas and his Istanbul Party colleague Imamoglu are thought to be potential candidates for the 2028 presidential election.
Ahead of Sunday's Istanbul election, the incumbent mayor faces a strong challenge from AK Party candidate Murat Kurum, and the vote was seen as close to being decided.
President Erdogan led his party's election campaign, vowing to usher in a new era in Turkey's megacity of about 16 million people.
But his government has been unable to shake off an economic crisis with inflation at 67% and interest rates at 50%.
With a majority of votes counted in Istanbul, CHP's Imamoglu had a nine-point lead over his rival AK Party.
“Based on the data we currently have, I can say that the public's trust and confidence in us has been rewarded,” he said.
In Ankara, CHP mayor Mansour Yavas was leading by a wide margin, but the number of votes counted was small.
Significantly, their party was also ahead in many of Turkey's other large cities, including Izmir, Bursa, and the resorts of Antalya.
Mr. Erdoğan's AK Party has had greater success in areas of the southeast affected by the February 2023 double earthquake. Kahramanmaras and Gaziantep cities were ahead of the curve.
Some 61 million Turkish voters were eligible to take part in Sunday's election, with turnout estimated at more than 76% in the country's 81 provinces.