Juan Carlos Garrido has lasted only 48 days as Real Betis coach, with the Andalusian club sacking him on Sunday night.
The decision was taken in the wake of Saturday's 5-0 home drubbing by Real Madrid which left Betis five points adrift at the foot of the table.
They have won just two games all season, although Garrido is not entirely at fault, with Pepe Mel, now at West Brom, having been in the chair before him.
The 44-year-old leaves without winning a single Spanish La Liga match, though, while his two victories, in the Copa Del Rey, mattered little as his men were beaten by Athletic Bilbao in the second leg of their tie this week.
Betis announced the decision on their official website, saying they had a man lined up to take over.
"Juan Carlos Garrido is no longer the coach of Real Betis," read a statement.
"The club has decided to dispense with his services. The coach, who has not achieved the desired results, will not lead the team tomorrow. The intention of the board is that the new coach, who arrives tonight, will immediately take over the team.
"The club wishes to acknowledge the work and dedication of Juan Carlos Garrido and his staff during these months and wishes him luck for the future."
Later on Sunday, Gabriel Humberto Calderon was handed the reins.
The 53-year-old Argentine played for Betis between 1983 and 1987 and arrives having most recently taken charge of the Bahrain national team.
"Humberto Calderon is the new coach of Real Betis Balompie," said a statement on the club's website.
"The coach, who arrived in Seville this evening, has already signed a contract for the rest of the season and an extra season should the club stay up."