Villa Real fans displayed a huge flag paying tribute to the 96 Liverpool fans who died in the 1989 Hillsborough disaster as the two teams clashed in the Europa League.
The home fans unfurled the large yellow banner as the Reds played their first match since the conclusion of the Hillsborough inquest.
It reads: "96 You Never Walk Alone" alongside the Villareal logo.
The inquest jury concluded the 96 victims were unlawfully killed in a crush during their side's FA Cup semi-final tie against Nottingham Forest. It also exonerated Liverpool fans of any blame.
Football fans have praised the move as "classy" on social media.