Alvaro Negredo missed a penalty for Cadiz as the hosts remained in the Liga relegation zone ahead of the final day of the season despite a spirited 1-1 draw against runaway champions Real Madrid.
Home fans at the Estadio Nuevo Mirandilla endured an agonising evening as Cadiz threatened a shock against the Champions League finalists after Ruben Sobrino emphatically replied to Mariano Diaz's fifth-minute strike for Madrid.
The Pirates will deservedly feel frustrated not to have earned three precious points in their battle against the drop after responding impressively to Diaz's opener.
Rodrygo's dazzling run deceived the home defence, culminating in the winger - one of the key architects of Madrid's dramatic Champions League semi-final win over Manchester City - supplying Diaz with a straightforward finish.
Andriy Lunin, Madrid's 23-year-old Ukrainian goalkeeper, deputised for Thibaut Courtois and produced several fine saves but could not stop Sobrino's powerful 35th-minute leveller.
The forward toyed with the Madrid defence on the centre of the visitors' penalty area before crashing in a thunderous shot that hit Eder Militao, cannoned off Lunin's crossbar and ended in the beaten goalkeeper's net.
Militao almost atoned for his part in the goal when he headed wide of the far post from a right-wing cross before half-time.
The real drama was to come after the break, when Lunin pawed former Madrid and City hitman Negredo's 61st-minute penalty away.