Argentina's President Nestor Kirchner has strengthened his support in legislative elections, in which his wife won a Senate seat.
The result is a victory for President Nestor Kirchner
President Kirchner's supporters now control the Senate and will form the largest bloc in the lower house.
Cristina Kirchner was elected to represent the province of Buenos Aires by a wide margin.
Mrs Kirchner said people had voted for a government that was reversing the country's economic fortunes.
"These people supported a model for the country that is beginning to change the lives of Argentines," she told cheering supporters in a victory speech.
According to exit polls, Mr Kirchner's allies will firmly control the Senate with 40 of 72 Senate seats, and 85-100 seats in the lower house of 257 deputies - still short of a majority.
Final results are expected on Monday.
The vote has put Mr Kirchner in a good position to win control of his Peronist Party and run again for president in two years time, says the BBC's Tom Gibb in Buenos Aires.
Mrs Kirchner ran against Hilda Duhalde, spouse of former president Eduardo Duhalde and part of a rival faction of the ruling Peronist Party.
Both women are expected to get Senate seats under Argentina's complex voting system in which, in some areas, more than one candidate is elected.
In another prominent race, Mauricio Macri - a businessman who leads Argentina's popular Boca Juniors football club - finished first in the voting in the capital, Buenos Aires.
Exit polls suggest Mrs Kirchner defeated her opponent by 25 points
He beat Foreign Minister Rafael Bielsa, who was backed by the president.
Meanwhile, former President Carlos Menem, now 75, lost against a candidate sponsored by Mr Kirchner but is also still expected to take a Senate seat.
Many Argentines blame Mr Menem's decade in power in the 1990s for the country's subsequent economic collapse.
Mr Kirchner came second in the first round of the 2003 presidential vote and won by default when Mr Menem dropped out of the second round.
The president, who won a mere 22% of the vote in the 2003 election, has been holding rallies in and around the capital almost on a daily basis in support of candidates this time.
He has been urging Argentines to support him in his effort to restore the country's economy after its meltdown in 2002.