Celta welcome back top scorer Iago Aspas after a month out injured on the subs' bench.
The hosts made the breakthrough in the 13th minute as Bale broke onto a fine Modric pass before finishing into the corner via the post. Acraf got the fourth goal for Real Madrid after he was set up by Karim Benzema in the 52nd second minute with Real Madrid dictating proceedings at the Bernabeu.
But the Frenchman's attention was quickly drawn back to the matters unfolding before him in the Spanish capital as Jozabed eventually bundled the ball into the Los Blancos goal, only for - somewhat unconventionally - referee Pablo Gonzalez Fuertes to rule the strike out for offside - a correct call, yet one the linesman should have spotted.
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Koos made it six for the home side with just nine minutes to end the game.
Celta came close to registering late in the first period when Daniel Wass headed towards the bottom corner, only for Real Madrid goalkeeper Keylor Navas to make a wonderful save.
Isco then flicked a Benzema effort into the Celta goal in the 58th minute, but the offside flag cut the home side's celebrations short, before Alvarez just beat Bale to a through ball from Kroos. Real Madrid got the second goal from a Bale's screamer as the Welsh forward ran down the wing to score a brace for Los Blancos. There was to be no hat-trick for Bale, however, with the Welshman replaced in the 72nd minute of the contest.
Toni Kroos rounded off the scoring for the home side in the closing stages of the second half as Los Blancos proved too strong for Celta Vigo on the night.
Bale nearly got his hat-trick but his effort was saved by the Celta Vigo goalkeeper, Zidane substituted Karim Benzema for Borja Mayoral in the 64th minute and Isco was removed for Marco Asensio and in the 72nd minute Bale was substituted for Lucas Vazquez.
Madrid battle Villarreal in their last game of the season and they will hope they can finish on the log ahead of Diego Simeone's men, while Celta Vigo face Levante.