Madrid increased its lead over second-placed Sevilla to eight points before it plays Getafe on Sunday.
Benzema converted a penalty earned by Casemiro just before halftime on Saturday to reach 300 career goals for Madrid. He helped set up Vinícius to double the lead in the 52nd minute after the Brazilian winger slalomed past several defenders. Shortly after, Vinícius finished off a rebound for the third.
After Goncalo Guedes pulled one back for Valencia, Benzema took his league-leading tally to 17.
Carlo Ancelotti's side missed Vinícius' verve last weekend in a shock loss to Getafe. Vinicius was sitting out the first of two games after testing positive for COVID-19.
Against Valencia, the forward again showed why he is a big reason Madrid is on course to reclaim the league title from Atlético Madrid. Vinícius has developed the finishing touch and decision making — to go with the quickness and dribbling skill he showed when he arrived at Madrid as a teenager — to become the competition's breakout player.
All his talents were there in his first goal.
With four defenders in his path, Vinícius took them on. He blew past two, exchanged quick passes with Benzema, and slipped the ball past the last two men before beating the hapless Jasper Cillessen.
His next goal was his 11th, leaving him behind only Benzema on the league's scoring list.
Benzema added a second goal with two minutes to play when he received the ball, spun and drilled a low strike into the corner.
"I have always felt good with Vinícius. I know his potential and that he can do even more," Benzema said after his 301st goal for Madrid.
"It is a source of pride to reach such numbers with this club, which I think is the best in the world."
Ten-man Barcelona conceded a late goal to draw at Granada 1-1 after Dani Alves set up the opener in his first league match since returning to the club.
The 38-year-old Alves curled in a long ball for Luuk de Jong to steer home with a header in the 57th.
But Granada poured forward after teenager Gavi Páez got his second booking with 10 minutes left. Antonio Puertas scored the 89th-minute equalizer with Barcelona hemmed in in its box.
Alves, who helped Barcelona win 23 titles from 2008-16, started his second stint on Wednesday as third-tier side Linares was beaten 2-1 in the Copa del Rey.
Barcelona was left in sixth place after missing the chance to climb into third and the Champions League spots.
"We are angry and frustrated because we let two vital points slip away," coach Xavi Hernández said.
"The sending off obviously changed the match, but we were already making too many mistakes, losing too many silly balls. It may be due to the lack of experience of our young players, but it is proving difficult for us to maintain possession when we need to."
Barcelona next heads to Saudi Arabia to play a clásico against Madrid on Wednesday in the semifinals of the Spanish Super Cup. Atlético and Athletic Bilbao are in the other semifinal.
FINALLY, A WIN
It took Levante 20 matches, but it finally got its first win of the season.
Roberto Soldado and José Morales scored in its 2-0 win over Mallorca after having gone the entire first half of the season — a full 19 rounds — without a single victory.The only previous win in any competition for the Valencia-based side came against a lower-division opponent in the Copa del Rey, before it was eliminated in the next round by a third-tier opponent.
Levante remained in last place, five points from safety.
Mikel Oyarzabal scored his 12th goal in all competitions to help Real Sociedad beat Celta Vigo 1-0, ending its six-round winless streak.