Espanyol have completed the signing of Raul de Tomas from Benfica for an initial fee of €20 million (£17m/$22m).
The 25-year-old has signed a six-and-a-half-year deal to become the first arrival since head coach Abelardo took charge last month.
The deal also includes €2m in add-ons and Benfica will retain a 20 per cent sell-on clause for the forward.
The fee smashes the club's previous transfer record of €10.5m, which they paid to sign Matias Vargas from Velez Sarsfield last July.
De Tomas, who joined Real Madrid at the age of 10 and progressed through the club's youth system, enjoyed productive loan spells with Real Valladolid and Rayo Vallecano before joining Benfica on a five-year deal in July.
Despite an impressive scoring record for Rayo and Valladolid, he managed only seven appearances in Portugal's top flight and did not score a single goal.
— RCD Espanyol de Barcelona (@RCDEspanyol) January 9, 2020
Espanyol were reportedly keen to sign him last year as a replacement for Borja Iglesias, who joined Real Betis in a €28m (£24m/$31m) deal.
Sevilla were also said to be interested in bringing him back to Spain this month after allowing Munas Dabbur to sign for German side Hoffenheim.
De Tomas, who scored 14 goals in 33 appearances for Rayo in La Liga last season, will be tasked with finding the goals to help drag Espanyol out of the relegation zone.
Espanyol have scored just 14 goals in 19 league games this season, two of which came in the 2-2 draw with city rivals Barcelona last Saturday.
Abelardo's side are bottom of La Liga on 11 points, four adrift of safety, having won just twice all season in the top flight.
Espanyol's last victory in the Spanish top flight came in late October, when they edged past Levante, and their next game is away to Villarreal on January 19 followed by a home clash against Athletic Club the following week.