Wales Sevens head coach Paul John has announced he will join Cardiff Blues as backs coach.
John became Wales Sevens head coach in 2008, after successfully coaching Pontypridd in the Principality Premiership - following an impressive playing career.
In his first season in charge of Wales Sevens, John steered the side to World Cup Sevens glory in Dubai, in March 2009.
The following September, John was appointed to the WRU National Academy on a full time basis in order to further develop Sevens in Wales.
Since Wales returned to the IRB Sevens circuit in 2005, 28 players have become full internationals after playing for Wales Sevens and John played a significant role in the development of those players, and many others who have gone on to have successful regional careers, and he has also been instrumental in increasing the use of Sevens as a development tool and game in its own right within schools, colleges and universities in particular.
Wales Sevens assistant coach Gareth Williams has been appointed interim head coach and will be at the helm for the next two rounds of the IRB Sevens World Series.
Paul John said: "The last six years working at the Welsh Rugby Union have been the most challenging and rewarding of my career. It's been a brilliant environment to be part of and all members of the Wales Sevens management team have been a particular joy to work with.
"For that reason, I certainly wasn't looking to leave the WRU and it has been a very difficult decision to make.
"However, I know Phil Davies and obviously worked closely with Dale McIntosh for a very long time, which has made the option more of a realistic possibility. Coaching the Blues will certainly be a challenge but on reflection it was a decision I felt I could live to regret if I didn't make the move."
John will continue to head up the coaching team with Principality Premiership champions Pontypridd.
"Having discussed the situation with Phil Davies and my family, and without the Wales Sevens related travel, I feel I will have time to devote to both jobs and that actually they will complement each other.
"I'm leaving the Wales Sevens set-up in great hands with Gareth Williams taking interim charge of the side, ably assisted by team manager David Jenkins and conditioner Wayne Proctor and the current squad is in excellent shape for the rest of the season."
WRU National Performance Manager Gethin Watts said: "We wish Paul John all the very best in his new role with Cardiff Blues. Paul has played a hugely important role in raising the profile and importance of Sevens rugby in Wales since taking over as Wales Sevens head coach and as a full time coach within the WRU's National Academy.
"He led Wales to an historic Rugby World Cup Sevens win in 2009, and importantly, utilised that success for the good of the game in Wales.
"The WRU regards Sevens as a vital tool for identifying, nurturing and developing Welsh talent, it is a clear pathway to producing players for the National Team as we've seen with the likes of Alex Cuthbert, Justin Tipuric, Rhys Patchell and Lloyd Williams in recent times and Paul did a huge amount of work in the development of those players and behind the scenes to encourage schools, colleges and universities to use Sevens as an additional or alternative form of the game.
"We are fortunate to have somebody of Gareth Williams' ability to take charge at this time. He, together with the rest of the management team are very experienced in their own right and will lead the Wales Sevens side into the next two tournaments.
This is a great opportunity to further develop a young, ambitious and very capable young coach whilst maintaining continuity in our development system."