Real Madrid capitalised on slip-ups by their two main title rivals to open up a four-point lead at the top of La Liga.
Matea Kovacic's first-ever La Liga goal put Zinedine Zidane's men on their way to a 3-0 win over Real Sociedad that enabled them to bounce back from a humbling Copa del Rey exit at the hands of Celta Vigo.
Cristiano Ronaldo was also on target at the Bernabeu, for the 20th time for his club so far this season, and Alvaro Morata added the third as Real completed the double over Sociedad and frustrated their bid to move into the top four.
With second-placed Barcelona held to a 1-1 draw at Real Betis and Sevilla going down 3-1 to Espanyol, Real are now firmly on course for a first league title since 2012 and a 33rd overall.
Barca boss Luis Enrique called for Spanish soccer to introduce goalline technology after his side were denied by a poor decision at Benito Villamarín.
The champions were left fuming when Betis defender Cristiano Piccini diverted Aleix Vidal's pass towards goal and the ball appeared to cross the line by around a metre.
The match officials did not award the goal and defender Aissi Mandi slid in to scramble the ball away, denying Barca an equaliser moments after Alex Alegria had put Betis ahead in the 75th minute.
Mandi came to Betis's rescue again moments later to clear another deflected cross from Vidal just before it reached the line, sparking further protests, mistaken on this occasion, from the visiting side.
The ball was about a metre over the line - Luis Suarez
Luis Suarez eventually equalised in the 90th minute although Barcelona missed the chance to provisionally go top of the standings and put pressure on title rivals Real Madrid and Sevilla.
"I've seen the photo but the referees need help, whether it's with technology and in cases when it ends up hurting us or benefiting us," Enrique said.
Barcelona director Javier Bordas also demanded that Spain followed other European leagues and other sports in using technology.
"We have to stress that we have to have technology in football right now. It's in almost every other sport and I don't know why it's taking so long," he told BeIN Sports.
"It was a very evenly matched game and anything could have happened, but the fact is we scored twice and they only counted one of our goals. That's something that could be fixed."
