[6] Two months and two days later, he scored his first top-flight goal in a 2–2 draw with Andalusian neighbours Granada at La Rosaleda Stadium, finding the net four minutes after replacing Duda.

[8] On 24 July 2017, having paid his own €12 million buyout clause to leave Málaga,[9] Fornals moved to fellow top-division side Villarreal, a club he already represented as a youth, agreeing to a five-year contract.

[10] The following 13 January, he scored a late chip after a counterattack to give his new team their first-ever win against Real Madrid at the Santiago Bernabéu Stadium (1–0).

[14][15] He made his Premier League debut on 10 August, in a 5–0 home defeat by Manchester City coming on as a half-time substitute for Michail Antonio.

[18] The following season he featured in all twelve of his side's Europa League games as they reached the semi-finals,[19] providing two assists in the 3–0 win at Olympique Lyonnais in the last-eight.

[26][27] In the late hours of 1 February 2024, deadline to the winter transfer window, Fornals agreed to join Real Betis for a rumoured €6 million fee, pending on approval.

[40] Making his first start on 8 September, against Kosovo in a 2022 FIFA World Cup qualifier, he scored his first goal for the national side when he opened a 2–0 win in Pristina.