Cadiz's Primera Liga survival hopes are hanging by a thread despite scoring a last-gasp equaliser to keep Real Sociedad sweating on their own top-flight future.

Lucas Lobos scored from the spot to complete a dramatic comeback after Sociedad looked to have all-but secured their survival by taking a 2-0 lead.

Xavi Prieto and Gaizka Garitano struck for the visitors early in each half but Fabian Estoyanoff cut the deficit within three minutes of coming off the bench and the hosts even a had goal disallowed before Lobos' spot-kick.

Sociedad arrived at the Estadio Ramon de Carranza knowing a win could guarantee their Primera Liga status and they began with that mission firmly in mind.

They were ahead inside eight minutes when Daniel Cifu pumped a free-kick into the area, which was nodded back across goal by Gari Uranga.

The ball found Prieto, who peeled off his man before firing a low volley past a motionless Alejandro Limia and into the bottom corner for his eighth goal of the season.

The visitors had Asier Riesgo to thank for preserving that lead moments later, the goalkeeper pulling off an outstanding close-range save from Jonathan Sesma, who had been found by Mariano Pavoni.

The stop was all the more remarkable because Riesgo managed to get fingertips to the ball despite colliding with his own defender.

Cadiz's desperation was almost tangible, and their pressure nearly forced an equaliser half-an-hour in when Sociedad failed to clear a Lobos free-kick.

The ball fell to Andres Fleurquin 12 yards out, but the Uruguayan could only blast wide of the near post.

Five minutes before half-time Cadiz again squandered a good opportunity when Enrique Ortiz found Luciano Vella in space on the edge of the box.

The full back burst into the area but his shot was blocked by a last-gasp challenge by Igor Jauregui.

Sociedad looked to have suffered a blow when Riesgo was forced off injured, but Alberto Lopez quickly settled between the posts with a sprawling save from Enrique's drilled free-kick.

All Cadiz's hard work appeared to have gone to waste three minutes after the restart when Mark Gonzalez's corner from the left found Garitano, who didn't even have to jump to head the ball into the net from eight yards.

Cadiz refused to surrender, head coach Victor Esparrago throwing caution to the wind.

Within five minutes it paid dividends as the newly-introduced Estoyanoff took advantage of some slack defending at a throw-in to steal into the box unnoticed before firing an angled drive inside the far post.

Cadiz thought they'd salvaged a point in the final minute when Oli Alvarez bundled the ball home from close range, but the veteran striker was adjudged to have committed an offence in the build up and the goal was disallowed.

However, the home side were not to be denied and with time almost up Cifu's rash tackle on Fernando Moran gave them the chance to equalise from the spot.

Lobos kept his composure to send his kick high past Alberto but it is almost certainly too late for Cadiz, who look like needing to win both their remaining games to stand any hope of survival.

Sociedad cannot afford to relax either - with Alaves beating Real Betis, they are now only two points clear of the drop zone.