Coming into the contest with a three-point buffer to the drop zone, Alaves made a dream start against their Basque rivals with a breakthrough inside three minutes.
Abderrahman Rebbach’s low delivery into the box looked simple to clear for Duje Caleta-Car, but the Croatian centre-back inexplicably diverted the ball into his own net to gift the visitors an early lead.
Undeterred by that setback, Sociedad went in pursuit of an immediate response, and Matarazzo’s side drew level in the 14th minute when Luka Sucic picked out the bottom corner with a superb 25-yard strike.
The end-to-end nature of the match continued as the first half progressed, with both teams finding the net in the space of three minutes.
First, Ibrahim Diabate found himself in the right place at the right time to clinically convert a loose ball for Alaves, before La Real restored parity once again as Benat Turrientes’ spectacular long-range effort struck the post and deflected in off the back of Antonio Sivera.
The hosts looked to up the ante before half-time, and they went close to moving ahead when Ander Barrenetxea saw a promising effort blocked in the box.
Having won their last three LaLiga head-to-heads, El Glorioso started the second period on the front foot, seeing plenty of the ball in the final third.
It was Sociedad, however, who scored the game’s fifth goal on the hour mark, as Takefusa Kubo’s inch-perfect cross was headed home by Orri Oskarsson for the Icelandic striker’s sixth goal of the season.
Alaves pushed for an equaliser with time ticking into the final 25 minutes, but Lucas Boye twice failed to convert from close range, as the hosts’ rearguard held firm under pressure.
Toni Martinez spurned another glorious chance for the visitors late on, while Sociedad were reduced to 10 men following an ugly challenge from Sergio Gomez.
Keen to make the most of their numerical advantage in the closing stages, Alaves threw everyone forward in the hope of finding a last-gasp leveller, and it duly arrived in the seventh minute of stoppage time when Boye fired a terrific strike into the corner beyond Alex Remiro to snatch a dramatic point at the death.