Watford have sold Odion Ighalo to Chinese Super League club Changchun Yatai.
The 27-year-old striker leaves after two-and-a-half years at Vicarage Road for an undisclosed fee.
Ighalo scored 39 goals in 100 appearances for the Hornets including 20 as Watford secured promotion to the Premier League in 2014/15, and 17 during the club's first campaign back in the top-flight last season.
The Nigerian international initially arrived on loan from Granada in July 2014, a move which was made permanent three months later.
Ighalo was also linked with a move to West Brom but that would have only been as a direct swap for Saido Berahino, who did not want to move to Watford.
The Baggies were not keen to buy the striker outright.
In January, Watford have signed two forwards in AC Milan striker M'Baye Niang on loan and Argentinian forward Mauro Zarate on a permanent deal from Fiorentina.