Koke's early goal proved enough for Atletico Madrid to claim a 1-0 win at Getafe on Saturday as they extended their lead over Real Madrid in the race to finish second in La Liga.
Atletico goalkeeper Jan Oblak also saved a late penalty from Faycal Fajr as Diego Simeone's men warmed up for Wednesday's Europa League final against Marseille by denting Getafe's hopes of playing continental football next season.
Simeone resisted the temptation to rest players for the final in Lyon and was rewarded as his side moved six points clear of third-placed Real with one game to go, before the European champions host Celta Vigo later on Saturday.
The capital club got off to a quick start in the local derby, as Koke collected Antoine Griezmann's pass and drove a low shot into the bottom corner to score his fourth goal of the campaign in the eighth minute.
Getafe missed a chance to stay just two points adrift of seventh-placed Sevilla in the chase to qualify for the Europa League, as Fajr's 77th-minute spot-kick was kept out by Slovenian Oblak.
Sevilla would have wrapped up a top-seven finish with victory in their derby at Real Betis, but Loren's equaliser with nine minutes to play snatched the home team a 2-2 draw.
Managerless Sevilla, who reached this season's Champions League quarter-finals, now have to beat Alaves next weekend to secure a spot in Europe's second-tier competition.
Elsewhere, Samu Castillejo scored twice as Villarreal beat relegated Deportivo La Coruna 4-2 to leapfrog Betis into fifth, with Denis Cheryshev also netting a day after being recalled to the preliminary Russian World Cup squad.