Argentine President Cristina Kirchner was recovering "without complications" Wednesday after surgery that successfully removed a blood clot on her brain, her doctors said.
"Her spirits are very good," according to the medical report.
Kirchner, 60, underwent surgery on Tuesday after being diagnosed over the weekend with a "chronic subdural hematoma" resulting from a blow to the head sustained in mid-August.
"On the first post-operative day, Kirchner is evolving favorably without complications," the report said.
"Her vital signs are within the normal range" and she remains under close medical supervision, it added.
Kirchner "rested very well all night. She is keeping her spirits up and also has already started eating," added her spokesman Alfredo Scoccimarro.
Vice President Amado Boudou, a former economy minister, has assumed day to day running of the government, although without a formal transfer of presidential powers.
The 50-year-old Boudou is under investigation for alleged influence peddling on behalf of a graphics company, although no charges have been filed in the case.
"Decisions are made by the president, who gives the instructions, and they are executed by the acting president," Cabinet chief Juan Manuel Abal Medina said on Del Plata radio.
In the first weeks after her operation, the president will have to take some modest precautions; one of her surgeons noted that air travel is off limits for some time.
Kirchner's convalescence comes as the country heads into midterm legislative elections October 27 that are likely to set the political tone for the last two years of her presidency.
At stake are half the seats in the lower house of Congress and a third of the Senate. Kirchner's Peronist party currently controls both houses, but showed signs of weakness in primaries earlier this year.
Argentine-born Pope Francis sent the president his best wishes and a prayer that Kirchner would "be strengthened so you can be able to return to your duties."
Kirchner has presided over rising inflation, a weakening peso and a greater government role in the economy, including unpopular controls on how many dollars people may hold.
Internationally, she has kept up her country's push for talks at the United Nations on the sovereignty of the British-ruled Falklands, which Buenos Aires claims.