Premier League club Southampton fired manager Nigel Adkins on Friday, and hired Mauricio Pochettino in his place.
Adkins lost his job despite presiding over an unexpected 2-2 draw at Chelsea on Wednesday, which put the south-coast team three points above the relegation zone.
"This decision has been made with the long-term ambitions of Southampton Football Club in mind,'' executive chairman Nicola Cortese said.
After arriving at Southampton in 2010 with the team in the relegation zone of the third division, Adkins secured back-to-back promotions to enable the club to return to the top division after a seven-year absence.
Pochettino, who has been out of work since leaving Spanish club Espanyol in November, will take charge of Southampton for the first time against Everton on Monday.
"This is the kind of opportunity that any coach would relish,'' the former Argentina defender said. "Southampton is a club with great heritage, and an even more exciting future. There is a clear vision to take the club to a new era of sustained success in the Premier League, and beyond, which I'm delighted to be part of.''
Cortese expects the 40-year-old Pochettino to be able to lift the team up and away from the relegation zone.
"Mauricio is a well-respected coach of substantial quality who has gained a reputation as an astute tactician and excellent man manager,'' Cortese said. "I have every confidence that he will inspire our talented squad of players to perform at the highest possible level.
"He also shares my belief that the most successful clubs are built by nurturing young players through a development system that provides a clear path to the first team.''
But Southampton did sign Norway defender Vegard Forren from Molde on a 3 1/2 year deal on Friday.