The home side were not finished in the first period, however, with Sami Khedira making it 4-0 at the interval.
Sociedad opened their tally just past the hour mark when Antoine Griezmann found the back of the net, before Ronaldo completed the scoring with a free kick 15 minutes from time.
Here, Sports Mole dissects the 90 minutes of action between the two Spanish rivals.
On target: 8
On target: 3
Was the result fair?
In truth, Madrid deserved to run out convincing winners at the Bernabeu this afternoon. They blew Sociedad away in the first period and but for some poor finishing, it might have been six or seven at the interval. To Sociedad's credit, they emerged with a different attitude in the second half, but the damage had already been done. It would be fair to say that the home side were four goals better than their opponents in the Spanish capital.
Real Madrid's performance
The former Spanish champions might still have problems in defence, but with their attacking options, they must be considered as contenders for every competition that they enter. The combination play between Ronaldo, Gareth Bale and Benzema was stunning, especially in the first period, while Xabi Alonso's return has brought calmness to their midfield. All they can do at this stage of the season is continually ask questions of Atletico Madrid and Barcelona.
Real Sociedad's performance
Sociedad entered the match on the back of a 0-0 draw with Manchester United in the Champions League, but they were unable to produce that level of performance this afternoon. Last season's fourth-place finishers were extremely poor in the first period as they allowed Madrid to cut through them on the counter, but they must be credited for their performance in the second half. It would have been easy to retreat into their shell, but they had a go at the hosts in the final 30 minutes of action.
Sports Mole's man of the match
Cristiano Ronaldo: What more is there to say about the Portuguese? His three goals this afternoon means that he has now scored 16 times in La Liga this season. That leaves his total as 24 goals in 17 matches in all competitions. His third in particular - a thumping free kick - was sensational.
Biggest gaffe of the match
Alvaro Morata had a glorious chance to score Madrid's sixth in the latter stages, but somehow he fired Ronaldo's cross wide of the target when it looked easier to score. Of course, it mattered little in terms of the final result, but it would have been another confidence-booster for the youngster.
It was a tale of two penalties for referee Juan Martinez. The Spaniard awarded Madrid a spot kick after Markel Bergara handled inside his own box, but failed to award one to Griezmann after the Sociedad midfielder went down under a challenge from Diego Lopez in the second half. In truth, both were difficult calls, but both or neither should have been given. Overall, neither manager will have had too many complaints about the Spaniard's performance in the Spanish capital.
Real Madrid: Carlo Ancelotti's side return to league action after the international break with an away match against a resurgent Almeria side.
Real Sociedad: Sociedad also return to action on November 23 as they host Celta Vigo.