Salisbury City manager Mikey Harris has quit the troubled non-league side to work as youth team boss at Portsmouth.
Harris, 29, became English football's youngest full-time manager when he was promoted from assistant last summer.
He led the Whites to a 12th-place finish in the Conference Premier this term but they were demoted one division for failing to pay debts.
Hampshire-born Harris said in a statement: "The opportunity to work at Portsmouth is one that excites me."
He continued: "It is a huge club with an incredible set of fans and the club I grew up with. I am delighted to take up the role and look forward to working with the staff at Pompey to help develop the young players."
Harris signed a new contract in May but had become increasingly frustrated with Salisbury's financial plight.
The club have been under a Football Conference transfer embargo since April and it is thought staff wages have been delayed for the last two months.
Following their demotion, which was confirmed earlier this month, the club were told they must pay a £50,000 financial bond and all outstanding debts owed to football creditors by 4 July.
If they fail to meet the deadline, they will be expelled from the Football Conference altogether.
Harris was assistant manager at Salisbury in 2010 when they suffered a double demotion because of financial problems.
"I hoped it was something I would never experience again," continued Harris' statement. "I share the fans' disappointment that the club is not going to be competing in the top level of non-league football this season.
"I would like to thank the players, staff and supporters at Salisbury City for their support during my time at the club. I leave with some great memories of some special achievements."
Salisbury spokesman Paul Smith added: "Obviously we are extremely disappointed to lose Mikey but under the circumstances we appreciate why he has decided to leave - exercising a clause in his contract to join Portsmouth.
"He goes with our best wishes for the future. In the meantime the fight to save the club goes on."
Portsmouth's newly-appointed academy manager Mark Kelly also expressed his delight at Harris joining the League Two side's youth set-up.
"He's a young vibrant coach," Kelly said. "He's been cutting his teeth as a manger in the Conference and with what he had to deal with, he was quite successful and built a reputation at Salisbury.
"I managed to go and see one or two games and it was one of those situations where he liked to play football and try and do things the right way, so it's only going to be a plus around the young scholars."