Bale nets first Madrid hat-trick
The Welshman netted his first treble for the capital club, as well as creating the other goal for Karim Benzema, as Madrid's free-scoring form continued.
Carlo Ancelotti's side have now scored 18 goals in their past four games.
With the injured Cristiano Ronaldo watching from the Bernabeu stands, Bale started the rout by heading home a rebound shortly after the half-hour mark and three minutes later provided a fine cross for Benzema to nod the second.
The former Tottenham man followed up to slot home a loose ball in the area in the 64th minute and got his third a minute from time by converting a low Marcelo cross.
Third-placed Madrid's win kept them three points behind city rivals Atletico, who earlier won 2-0 at Elche.
Diego Simeone's side struggled to overcome Fran Escriba's disciplined outfit until Koke broke the deadlock on 62 minutes, and Diego Costa made sure of the three points 11 minutes later.
Atletico's win moved them level on points with leaders Barcelona, who have the chance to extend their lead on Sunday.
At the other end of the table Celta Vigo came from behind to claim a vital 3-1 win over fellow strugglers Almeria to climb away from the foot of the table.
Suso scored the opening goal for visitors Almeria in the 10th minute.
However, Fabian Orellana levelled for Celta before second-half scores for Borja Oubina and Charles sealed a win which moved them three points clear of the bottom three.
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