Champions Barcelona moved five points clear at the top of La Liga with a 2-1 win at Getafe, while Real Madrid fell to a 2-0 defeat by Real Sociedad.
Here are five talking points from the weekend's action.
Real Madrid's stumble against Real Sociedad saw them slump to fifth in the standings, 10 points behind leaders Barcelona.
Their performances under Santiago Solari, even when they win, have been uninspiring and as a result just 53,412 turned up to watch the match on Sunday, their second worst attendance of the campaign.
Little over an hour afterwards, Madrid announced the signing of Manchester City midfielder Brahim Diaz. It was an attempt to bat away crisis headlines, but it did not work.
The club are in "a crisis that never ends," said Madrid daily Marca, while editor Jose Luis Calderon singled out Solari for blame.
"If he weren't the second coach of the season and if Real Madrid hadn't already run out of ammunition then he'd be fired," wrote Calderon.
However, midfielder Luka Modric said fingers should not be pointed at the manager.
"You cannot blame the coach, he's doing a fantastic job and it's not him failing to score goals or keep them out at the other end," said the Croatian, turning the blame on the players.
A year on from signing for Barcelona from Liverpool in a 160 million euro ($183.1 million) deal, Philippe Coutinho did not imagine he would be relegated to the bench.
The Brazilian has started just one of the last six games in all competitions, the Champions League clash with Tottenham Hotspur which was irrelevant from a Barcelona perspective, with the Catalans already qualified top of their group.
Against Getafe he played the final few minutes as a late substitute and offered little, giving away the ball badly on one occasion.
"He is one of the best players in Europe and is ready to play for five minutes or 90 minutes," Barcelona director Guillermo Amor told Movistar.
Coutinho's New Year's resolution must be to force his way back into coach Ernesto Valverde's good books.
VALENCIA FROZEN OUT
Alaves moved fourth, ahead of Real Madrid, with a 2-1 win over Valencia at Mendizorroza on Saturday but visiting coach Marcelino was furious about the pitch.
The surface was icy, creating slippery conditions that made things difficult for both teams.
"Of course (it should have been postponed)," said Marcelino.
"I think that at 9AM you would know the pitch would be frozen at 4PM. In England the climate is much worse than here, and I've never seen half of a pitch frozen like we saw here today.
"We have to make sure that we have some of the best playing surfaces in the world. The players looked like dancers trying not to fall over, and this happened in 2019."
Valencia slipped to 12th in La Liga, continuing a disappointing campaign.
Atletico Madrid forward Antoine Griezmann scored a brilliant freekick to earn his team a 1-1 draw at Sevilla, although the result leaves his side second, five points behind leaders Barcelona.
The French striker had a glorious opportunity to win the game for the visitors in the final stages but fired straight at Tomas Vaclik, who denied him.
"With more accuracy from Griezmann, we could have won the game," said Atletico coach Diego Simeone.
But the Frenchman might feel his real mistake was not signing for Barcelona in the close season when he had the chance, with Atletico's project appearing to stall.
MESSI AND SUAREZ OUTGUN MADRID
Real Madrid have struggled to find the net this season in the absence of all-time top scorer Cristiano Ronaldo, who left for Juventus in July.
By contrast, Barcelona's strikers have been the league's most lethal.
Lionel Messi leads the scoring charts with 16 and is followed by team mate Luis Suarez on 12, the duo netting 28 goals out of Barcelona's 50.
The South American pair have outscored Madrid's whole side, with Los Blancos managing a paltry 26 in total.
Although goals have reappeared in the Solari era after the second longest drought in club history under his predecessor Julen Lopetegui, Madrid lack menace in attack.
As well as derailing their title challenge, it could also cost them in their bid to retain the Champions League for the fourth season running.