Southampton have sacked Mauricio Pellegrino as manager, the Premier League club announced on Monday.
Pellegrino was hired on a three-year deal in June of 2017 after Claude Puel was let go at the club. He had previously been at Alaves.
Saints were beaten 3-0 at Newcastle on Saturday and lie just one place and one point above the relegation zone.
Southampton have won just one of their last 17 league matches -- against bottom club West Brom -- with this weekend's defeat proving to be the final straw.
Assistant manager Carlos Compagnucci and assistant first-team coach Xavier Tamarit have also parted company with the south coast club.
A Southampton statement read: "We would like to place on record our thanks to Mauricio, Carlos and Xavier for their efforts during their time with Southampton, and wish them well for the future.
"The club will look to appoint a new management team as soon as possible, with the search for a replacement already under way.''
Saints will be hoping to appoint Pellegrino's successor quickly, with an FA Cup quarter-final at Wigan looming on Sunday.
They then face a crunch clash with relegation rivals West Ham at the London Stadium on March 31.
Former Hull and Watford boss Marco Silva has been installed as the favourite for the vacancy with bookmakers.
Pellegrino, 46, played for Barcelona, Valencia and Liverpool as a player, while his coaching career has included stints in charge of Valencia, Estudiantes and Independiente.