Ronaldo returned to the type of form that won him three World Player of the Year awards by getting two goals in Real Madrid's emphatic 3-0 victory at bottom club Alaves.
"This was a great victory. Football is like that and, in the end, the footballer with talent and quality is the one that makes the difference," said Real coach Wanderley Luxemburgo, paying tribute to the player he discovered.
The triumph will take the pressure off Luxemburgo after speculation that the Br azilian coach's job was in jeopardy after three consecutive losses before Real's 3-1 win over Athletic Bilbao on Thursday.
"But to win a game by three goals difference, you have to have a team working hard and everyone working together," added Luxemburgo.
Real dominated the first half but had to wait until 59 minutes before Ronaldo opened the scoring with a blistering left foot shot from 20 yards.
Three minutes later the Br azilian striker nearly had his second goal when he put a pass, from his compatriot and fellow World Cup winner Roberto Carlos, against the post.
Ronaldo's second goal came eight minutes from time when a long pass by David Beckham from his own half found the Alaves defence in disarray and Ronaldo in the right place to take advantage of the open spaces.
Jose Maria ' Guti' Gutierrez added Real's third three minutes into injury time.
The victory moves the Spanish giants up to third. By contrast, newly-promoted Alaves are now the only Spanish first division side without a win and are already two points adrift at the foot of the table.
Real's, and Ronaldo's, revival slightly overshadowed Celta Vigo's 2-1 victory over Sevilla, which took the Galicians back to the top of the table.
Fernando Baiano opened the scoring after just 41 seconds, connecting with a superb pass from Real Madrid and Liverpool reject Antonio Nunez.
Borja Oubina added Celta's second on 14 minutes, going past two Sevilla defenders before sliding the ball just inside the post.
Vicenzo Maresca's penalty brought Sevilla back into the game after 53 minutes, following a Pablo Contreras foul on Sevilla striker Fredi Kanoute but, despite pressure from the visitors, Celta hung on for their fourth win in five outings.
Second are unbeaten Getafe, who continued their remarkable season by winning 1-0 at near-neighbours Atletico Madrid on Saturday.
The only goal of the game came after 71 minutes from a Mariano Pernia free kick, his low and hard shot flying through Atletico's wall.
Malaga were in holiday mood at Real Mallorca, romping to a 4-1 win over the island side on Sunday.
Salva Ballesta opened the scoring for Malaga after 28 minutes followed just two minutes later by Portuguese midfielder Duda finding the net from a free kick.
Duda scored again from a free kick after 56 minutes and two minutes later it was the turn of another Portuguese player, Edgar, to embarrass Mallorca by chipping the ball over the head of Mallorca keeper Toni Prats from just inside the area.
Greek international Lambros Choutos got a late consolation goal for Mallorca.
Reigning champions Barcelona got their first domestic away victory with a 4-1 win at Real Betis on Saturday.
Dutch midfielder Mark van Bommel, starting his first game since moving from PSV Eindhoven in the summer, headed the visitors' opener after 19 minutes.
Juanito Gutierrez headed an equaliser for Betis eight minutes from the break but Barca, without the rested Ronaldinho and Deco, responded in the second half.
Samuel Eto'o atoned for missing a penalty after just nine minutes with two goals and Santi Ezquerro got his first goal for Barca two minutes from the whistle.