Mauricio Pellegrino has been appointed as the new Southampton manager on a three-year deal.
Despite guiding Saints to eighth in the Premier League and the EFL Cup final in his first season, frustrations behind the scenes and in the stands led to Claude Puel's sacking last week.
Southampton have acted quickly to name his successor, with former Alaves boss Pellegrino penning a contract at St Mary's.
"I am really happy to become the new coach of Southampton Football Club," Pellegrino said.
"The club has a great reputation for having a strong and stable structure, competing in the Premier League and playing attractive football.
"I think my philosophy and the culture of the club will work well together. We have to be a team on and off the pitch; I want to make the supporters proud of the players and to feel part of the game every week.
"I want to win matches, be successful and develop a team spirit where everyone gives 100 per cent and supports each other.
"I am excited and passionate about what the future holds for us and look forward to meeting the players and beginning our preparation for the new season."
Pellegrino becomes Southampton's second Argentinian manager, with Mauricio Pochettino previously at the helm.
The 45-year-old, a former international defender, will officially join up with the club next week, in time for the start of pre-season training.
Pellegrino last season led Alaves to the Copa del Rey final in his only campaign at the helm after spells in charge of Valencia, Independiente and Estudiantes.
The former Argentina international coached under Rafael Benitez at Liverpool and Inter Milan, with Les Reed, Saints' vice-chairman of football, impressed by both his philosophy and personality.
"I am delighted that after a diligent selection process we have recruited Mauricio Pellegrino as our new first-team manager," Reed said.
"We had an impressive list of candidates and went through a comprehensive interview process. Mauricio impressed us throughout with his depth of knowledge, motivation and ability, communicating this in a professional and passionate way.
"He has an excellent understanding of the Southampton way, and his style of play and aspiration matches the philosophy, culture and ambition of the club.
"We firmly believe Mauricio is the right person to help us take the next steps. He knows our players and believes we have a great squad that with some fine-tuning will be able to deliver continued success.
"Mauricio believes with the quality we have we can play exciting, attacking football, taking the game to our opponents by playing a high-intensity game.
"He will continue to develop and introduce young players whilst building on the core of experience that we have in the squad.
"During the recruitment process Mauricio quickly became our first choice and, while he had other options, we are delighted he feels that St Mary's is the right place for him and we believe he is the right fit for us.
"We are looking forward to working with Mauricio to take the club forward and achieve more success with this team."