Success joined the Hornets from Granada in 2016, signing a five-year deal with the club.
The forward began his career with Spanish side Granada. Initially part of the Granada B squad, Success progressed into the first XI, quickly becoming one of the most highly rates youngsters in Spain.
The 20-year-old, who can play in a central or wide attacking role, featured 56 times for the club scoring seven goals. A Nigerian Under-17 and Under-20 international, Success’ performances during the 2015/16 campaign also earned him the club’s Player of the Year award.
Success then agreed a five-year contract at Vicarage Road, completing a club transfer record breaking move. He scored his first Watford goal in a 2-2 draw at home to AFC Bournemouth.
The Nigerian spent the 2017/18 season on loan at Málaga CF.
The 2018/19 campaign saw Success score four goals in 35 appearances in all competitions, as the Nigerian forward came off the bench more often than not for one of Troy Deeney, Andre Gray or Gerard Deulofeu.