Newport Gwent Dragons director of rugby Lyn Jones has left by mutual consent after "a period away through illness."
Former Wales captain Kingsley Jones will take charge of the Welsh Pro12 region until the end of the season.
The Dragons are preparing for a European semi-final on Saturday and Jones' departure comes after weeks of speculation over his future.
"I have thoroughly enjoyed my three years at the Dragons," the 51-year old said in statement by the region.
"With the club transitioning into a new era of potentially new ownership and new investors, the time felt right for me to step aside.
"At the Dragons, we are seeing the emergence of an exciting generation of youngsters that can give the club a fighting chance of securing a place at the very top end of the game.
"I'm really proud to have played a part in this process. It's been immensely rewarding and I hope that it'll become the enduring legacy of my time with the Dragons."
The Dragons have lost seven games in succession in the Pro12 and have won just four league games all season.
Jones missed the last two Dragons games because of "illness" but was spotted at English Premiership club Harlequins with his rugby player son Luc.
Chief executive Stuart Davies, who earlier this month called for investment at Rodney Parade, explained that the Dragons brought forward an end of season review because of Jones' illness, despite the Dragons being in a European semi-final where they face French club Montpellier on Saturday.
"Whilst a frustrating and disappointing season is mitigated by a lengthy injury list and a record number of narrow defeats resulting in losing bonus points, taking the decision now affords Kingsley Jones, head coach, the opportunity to look after the side for the remaining games, ahead of us considering our options for next season," said Davies in a statement.
"Both parties agreed it was best for the side that there was a new voice at the helm going forward."
Jones returned to Wales following stints at an Abu Dhabi school and English club London Welsh.
The former Ospreys head coach appointed former Sale Sharks coach and namesake Kingsley Jones as his assistant and now the former Russia boss will step up and take charge at Rodney Parade.
Chairman Martyn Hazell added: "We would like to thank Lyn for all his hard work during his time in charge at the Dragons, and to wish him well in whatever challenge he takes on next.
"Whilst this season may not have quite delivered, we remain very excited about the talented young squad that he has assembled and are grateful to him for all he has done at the region."