The victory moved Real Madrid three points in front of third-place Barcelona, which routed Alavés 5-1 at home on Saturday.
Madrid continued their recent good form with a 2-0 win over Valencia in the Spanish league on Sunday, but coach Zinedine Zidane saw his already depleted squad lose another player due to injury.
Dani Carvajal got hurt before halftime in what had been his return to action after being sidelined since the beginning of the year.
"As a coach, I don't understand it," Zidane said. "There are too many injuries. I'm worried because when you lose a player, it upsets you. I'm sorry for Carva, he is an important player for us. I can't explain all these injuries."
Carvajal, who apparently felt a similar muscle injury that had kept him out of seven matches, was among a group of almost 10 players not available for Zidane in recent matches. That group includes captain Sergio Ramos and playmaker Eden Hazard.
Like most clubs, Madrid are enduring a tight schedule prompted by the coronavirus pandemic.
"I won't get into that," Zidane said. "We've already got a lot going on. It is what it is. We didn't have a normal preseason and we have a lot of injuries."
Karim Benzema and Toni Kroos scored first-half goals as Madrid comfortably beat Valencia to keep pace with leader Atlético Madrid.
Madrid's third straight league victory left Zidane’s team five points behind Atlético, which won 2-1 at Granada on Saturday and has two games in hand.
The victory moved Madrid three points in front of third-place Barcelona, which routed Alavés 5-1 at home on Saturday. The Catalan club have played one less game than Madrid.
"To be able to be at the top we can't fail anymore,” said Kroos, who like Zidane was concerned about how the injuries would affect the team.
"They worry us a lot because we are talking about important players and they will be missed " he said.
Madrid’s recent good run —- with four wins in five matches —- comes after they won only two of their previous seven games in all competitions.
"The improvement is obvious because we believe in what we are doing " Zidane said. “During a season you sometimes have problems and you have to overcome them. We are doing that and we have to keep going because there’s still a long way to go."
Valencia have won only two of their last 14 league matches and sit 13th in the standings, three points from the relegation zone. They had handed Madrid their worst loss of the season in November, winning 4-1 at Mestalla Stadium.
The result extended Madrid’s unbeaten streak against Valencia at home to 13 league matches, since a 3-2 defeat in 2008.
Benzema put Madrid ahead in the 12th minute with a low shot from outside the area after Kroos' pass. Kroos added to the lead in the 42nd, also with a low shot, after a setup by Lucas Vázquez, who replaced Carvajal and was also returning from injury.
Ferland Mendy, who scored in Madrid's league win against Getafe on Tuesday, had a goal disallowed for offside in the 61st.