The Portuguese also scored a hat-trick in Real’s 8-2 thrashing of Deportivo la Coruna on Saturday and now has 12 goals to his name in just eight appearances this season.
The Santiago Bernabeu had been briefly stunned as Ronaldo was penalised for a foul on Pedro Mosquera as he tried to clear inside his own area after 15 minutes and Edu Albacar slammed the spot-kick past debutant Keylor Navas in the Madrid goal.
However, the European champions responded in style as Gareth Bale headed home an equaliser before a Ronaldo penalty put them in front.
Ronaldo then produced a towering header to send the hosts in 3-1 up at the break before completing his hat-trick with another penalty and rounding off the scoring with a cool finish from Bale’s pass in stoppage time.
“To score four goals is very difficult. I thank my teammates for passing me the ball to be able to score,” said Ronaldo.
“It was a very good game for us. We started a little badly, I gave away the penalty, but we responded well with two quick goals.”
The build up to the game had been dominated by Real coach Carlo Ancelotti’s decision to hand Navas his debut ahead of the under fire Iker Casillas in response to his side’s defensive troubles so far this season.
However, the Costa Rican was left with no chance when Albacar slammed his penalty into the top corner to give the visitors’ the lead.
Things very nearly got worse for Real moments later as Marcelo was lucky to escape with just a yellow card after bringing down Garry Rodrigues on the edge of the box and Albacar curled the resultant free-kick inches wide.
Ancelotti’s men were gifted a route back into the game on 20 minutes when Bale made a good contact with James Rodriguez’s cross from the right, but Elche ‘keeper Manu Herrera should have kept the Welshman’s effort out at his near post.
Referee Clos Gomez then balanced up his decision to award Elche a soft penalty by pointing to the spot despite there appearing to be no contact between Mosquera and Marcelo as the Brazilian full-back tumbled in the box.
Ronaldo smashed the ball high into the net to make it 2-1 and was celebrating again four minutes later when he leapt highest to power Marcelo’s cross into the far corner.
Herrera atoned for his earlier error by beating away a fierce Ronaldo free-kick as he went in search of a second hat-trick in as many games and made an even better stop to deny Toni Kroos his first Madrid goal at the end of a lovely move involving Ronaldo and Rodriguez.
However, Ronaldo’s 25th hat-trick for the club finally arrived nine minutes from time when he slammed home another penalty after he had been clipped inside the area by Mario Pasalic.
And there was more to come from the 29-year-old as he raced onto Bale’s brilliant assist to slot home his fourth of the evening.
Victory takes Madrid up to fourth with Barcelona in action on Wednesday away to Malaga, whilst champions Atletico Madrid travel to Almeria.