The prolific Portuguese, who scored a record 40 goals last term as Real finished second behind Barcelona for a third consecutive year, fired compatriot Jose Mourinho’s side ahead in the 24th minute at the Romareda.
Brazilian fullback Marcelo and Spain midfielder Xabi Alonso made it 3-0, before Ronaldo, who has scored at least twice in his last five league appearances, netted two more goals either side of a gem from substitute Kaka.
The 26-year-old Ronaldo, who became the world’s most expensive player when he arrived from Manchester United in 2009, now has 69 goals in only 64 league appearances and 102 in 115 games in all competitions for Real.
“The team wanted to play well and get off to a strong start and we managed that scoring six goals at a difficult venue,” he told reporters.
“Firstly you have to congratulate the team for the win. I was able to score three goals thanks to my team mates.
“I help this team and this team helps me. We won’t win anything if we are not together.”
Real could easily have reached double figures and coach Mourinho, attempting to break Barcelona’s three-year stranglehold on the Spanish title, said his team had played a solid game.
“A match is generally over for any side when it loses 2-0 by halftime and concedes a third strike at the start of the second half,” the former Porto, Chelsea and Inter Milan manager told a news conference.
“We earned this result because we were excited to the very last minute.”
La Liga has kicked off a week late this weekend as last week’s first round of matches fell victim to a strike called by the players’ union (AFE) over unpaid wages, a dispute with the league (LFP) that was finally resolved on Thursday.
Athletic Bilbao’s bow at their San Mames arena was spoiled by promoted Rayo Vallecano, one of four Madrid-based clubs in the top flight this term, who fought back from a goal down to earn a 1-1 draw.
Big-spending Malaga, who were bought by a member of the Qatar royal family at the end of the 2009-10 season and have spent almost 60 million euros ($84.5 million) on players over the summer, went down 2-1 at Andalusian rivals Sevilla.
Michael Laudrup’s Real Mallorca made a winning start with a 1-0 victory over visiting Espanyol, while the club the former Denmark international used to coach, Getafe, also of Madrid, drew 1-1 at home to Levante.
