In November 2013, Success signed a pre-contract agreement with Italian side
Udinese, which would be effective from January 2014, for a
€400,000 fee. However, he was only granted a work permit in March of the following year, and immediately joined Spanish club
Granada, being assigned to
the reserves in
Segunda División B. On 31 August 2014, Success made his first-team debut, starting in a 1–1 away draw against
Elche at the age of 18 years and seven months, being their youngest player ever to appear in a
La Liga match. He scored his first professional goal on 7 December, netting his side's only of a home draw against
Valencia, for the same scoreline. On 7 August 2015, Success extended his contract with the club, signing a four-year until 2019 and being subsequently promoted to the main squad. On 1 July 2016, Success agreed a five-year deal with English
Premier League side
Watford in a record transfer fee, estimated around £12.5 million from Granada. He scored just once in 19 appearances in the
2016–17 season and, after just one appearance for the team in the
2017–18 season, was loaned back to Spain, joining
Málaga on 31 January 2018 until the remainder of the season. On 26 August 2021, Success left Watford after a five-year spell, signing for Italian club
Udinese on a three-year deal, the club he was previously linked to years before. On 27 August 2024, Udinese terminated Success's contract by mutual consent, making him a free agent. In October 2024, two months after leaving Udinese as a free agent, it was announced that Success had signed for highly decorated Emirati club
Al-Wasl on a free transfer. ==International career==