St Helens have parted company with head coach Royce Simmons just seven matches into the Stobart Super League season following the club's disastrous start.
Simmons, who was in the second year of a two-year contract, guided Saints to a fifth successive Grand Final last October but has paid the price for the club's worst ever run in the summer era.
Saturday's 12-8 loss at Bradford was their fourth straight defeat and they have taken just a point from their last five matches, their worst run since 1985.
Simmons' right-hand man Kieron Purtill has also stepped down and Saints have appointed head of performance Mike Rush as acting head coach, with former captain Keiron Cunningham as his assistant
St Helens chairman Eamonn McManus said: "Our season has got off to a difficult start and it is best to make change sooner rather than later.
"We have every faith in Mike Rush and Keiron Cunningham. They each know the club inside out and have all the experience together to take us forward."
The 51-year-old Simmons recently spoke about the pressure on him to deliver silverware to St Helens, whose last trophy success was in 2008 when they lifted the Challenge Cup under Daniel Anderson.
Saints have badly missed England hooker James Roby, who has sat out their last two matches through injury, but their dismal run began with a draw at Hull KR a month ago, followed by a dramatic last-second home defeat by Catalan Dragons.
They have subsequently also lost to Huddersfield, Hull and Bradford and face a Grand Final rematch with Leeds at Langtree Park on Sunday.
McManus added: "I would like to go on record to pay genuine tribute to Royce Simmons. He is a fantastic person and of absolute character and integrity, who has given everything to the club.
"I am sure that everyone at the club joins me in thanking him sincerely for all his work and dedication and to wish him and his family well for the future.
"Our sentiments are the same with Kieron Purtill. Force of circumstance has reconstituted change."
Rush and Cunningham will be in charge for the clash with the Rhinos but are likely to be only in temporary control while St Helens seek a permanent successor to Simmons.
Anderson, who was last week appointed as Exiles coach for the two-match series against England this summer, has already ruled out a return to St Helens, which leaves Huddersfield head coach Nathan Brown as the clear favourite.
Brown, who has turned the Giants into genuine title contenders during his three years at the club, last November confirmed his intention to step down at the end of this season and the club have already announced he will be succeeded in 2013 by his assistant Paul Anderson.
The former St George Illawarra boss was expected to return to Australia but, with top jobs in the NRL scarce, he will be tempted to stay in Super League if offered what is widely considered to be a glamour post with Saints.