Two goals in a five-minute blitz at the start of the second half blew Granada away as Los Blancos secured a comfortable win in their first league game following the winter break
Karim Benzema's opener was cancelled out by Mikel Rico, but Sergio Ramos reinstated Madrid's advantage before the interval. Gonzalo Higuain and Benzema struck early in the second period to stun the visitors, before Cristiano Ronaldo put the gloss on the final score with a late effort.
Mourinho's men started the game the brighter of the two sides and went close to scoring on a number of occasions inside the opening quarter of an hour. First, Ronaldo failed to convert a Benzema cross before Sergio Ramos looped a header over from a superb Xabi Alonso corner.
Los Blancos eventually broke the deadlock through Benzema, who swept home from six yards after wonderful build-up play between Ronaldo and Mesut Ozil, the latter of whom provided the assist for the French striker.
Despite their early dominance Madrid were soon pegged back by Granada, who equalised within minutes of Benzema's strike. Their goal came after Uche did well down the right-hand side to beat Marcelo and whip an inviting cross into the box where Rico was waiting unmarked to head in off the post.
After managing to withhold a storm of Madrid attacks early on and equalising, Granada began to put serious pressure on Iker Casillas and the Madrid defence. Rico nearly scored a second when he curled a fine effort towards goal that Casillas did well to parry to safety.
In a wildly open encounter Madrid then took a 2-1 lead against the run of play through Ramos. Ozil was again on hand to provide the assist, this time from a set-piece as his corner found defender, who planted a firm header past Roberto in the Granada goal.
The first half ended with both sides having speculative efforts on goal from distance as the game remained wide open after an entertaining opening 45 minutes.
After affording Granada space and time in the first half Madrid started the second half with a definite point to prove to the visitors. Two goals in five minutes did just that.
First Higuain fired past Roberto just 40 seconds into the restart after hesitant defending from Pape Diakhate. Benzema made it 4-1 three minutes later when he received a fine pass from Ozil on the edge of the box and demonstrated his ball-striking abilities by drilling home his second of the evening from 15 yards out.
Shortly after grabbing his second the France international had to be withdrawn through injury, making way for Jose Callejon. Ozil was then replaced by Kaka, as Mourinho gave his impressive playmaker a rest following a fantastic performance that included three assists.
The three goal cushion allowed Madrid to take a step off the gas in the second half, as Granada struggled to recover from the home side's blistering start to the second half.
Ronaldo, not to be outdone by the goalscoring exploits of those around him, got his name on the scoresheet with a well-struck effort from the edge of the area in injury time.
With the victory, Madrid move six points clear of Barcelona at the top of the table for at least 24 hours as the Blaugrana visit Espanyol on Sunday evening. Granada are 14th but may drop lower depending on the results for the rest of round 17.