Josh Maja has completed his move to Bordeaux.
The 20-year-old has signed a bumper four-and-a-half-year deal.
Sunderland had hoped for a positive resolution to the contract stand-off that has cast a shadow over their season but that changed at the beginning of the week when Maja made clear he wanted to leave the club.
The talented forward informed the Black Cats that he intended to sign a pre-contract agreement with a foreign club to move in the summer.
Sunderland would have landed a paltry compensation fee in that event, likely to be around the £300,000 mark.
In the summer of 2016 Moussa Dembele, then one of the brightest talents in the Championship, moved to Celtic.
Fulham received just £500,00 in compensation.
Dembele moved to Lyon for an estimated £20 million this summer.
The deal agreed with Bordeaux sees Sunderland initially net around £1.5 million for the 20-year-old, who has scored 16 goals next season.
That will rise should he activate a number of sell-on clauses included in the deal.
Should they all be activated then the Black Cats would land around £3.5 million.
They also have a sell-on clause if he leaves Bordeaux in the future.
It is understood that discussions are continuing over the exact payment plan, with Sunderland owing Bordeaux a similar amount to that initial fee from the deal that brought Wahbi Khazri to
Wearside in January 2016.
That means Sunderland's immediate cashflow could be unaffected by Maja's departure.
However, the club are pressing on with their plan to sign two strikers to help Jack Ross in his quest for promotion.
Stewart Donald told supporters on twitter that the Khazri talks would not affect business between now and the end of the window.
"[Bordeaux] are keeping some of it as we owe then money for July," he tweeted.
"It won't affect our ability to do deals over the next few days. Just means we have fewer legacy payments to make in July now but we did have those covered anyway.
"Club is debt free bar Legacy payments to players which we agreed to cover. We have mentioned that the club had a lot of these outstanding and I believe they finish in August.
"They total about £5 million now left to pay. We have them covered and have created a surplus."
Will Grigg remains a primary target, with Paul Cook confirming on Friday that he is set to miss two to three weeks with an ankle injury.
It had been initially feared that he would miss a much larger chunk of the season.
Regardless of the success of that particular pursuit, Sunderland remain confident that they will have two forwards through the door by the time the January window shuts next Thursday.