'Los Blancos' had been the better side early on but they were undone by a fin piece of play from the Basque outfit.
With 14 minutes on the clock, Raul Garcias was given time and space to pick out the perfect through ball for Williams.
The pass took Raphael Varane out of the game completely, allowing Williams to go in one-on-one, with the youngster keeping his cool to dink the onrushing Ketlor Navas and open the scoring.
It was an excellent finish from Williams, whose last 10 La Liga goals have all come away from home.
18 April 2018