Real Madrid s Brazilian forward Vinicius Junior celebrates after scoring his team s first goal during the Spanish League football match between Real Sociedad and Real Madrid CF at the Anoeta stadium in San Sebastian on December 4, 2021 (AFP)
The young attacking players struck goals early in the second half in San Sebastian to give Madrid its eighth consecutive win across all competitions and leave it eight points clear of nearest chaser Sevilla.
Madrid's victory came after Atletico Madrid and Barcelona were upset at home, leaving them further adrift.
"We knew that this was going to be a tough game at a difficult ground, but we played a great game from the very start," Madrid midfielder leader Luka Modric said. "It was a complete game and these are three huge points.''
Atletico Madrid trailed by 10 points in fourth place after the defending champion was stunned by Mallorca 2-1 in the capital.
Barcelona was a whopping 16 points behind in seventh place following a 1-0 loss to Real Betis, its first defeat since Xavi Hernandez took over as coach.
Manuel Pellegrini's Betis rose into third place, right behind crosstown rival Sevilla, which beat Villarreal 1-0 thanks to a goal from Lucas Ocampos.
Jovic never found his spot on Madrid following his 60 million euros transfer from Eintracht Frankfurt in the summer of 2019. He scored two goals in a season-and-a-half before he was loaned back to Frankfurt. Since his return in this campaign, he had tallied only just over 100 minutes as a sparsely used substitute, scoring zero goals.
But when Benzema gingerly walked off the pitch while grimacing in pain in the 17th minute, coach Carlo Ancelotti turned to Jovic to take his place.
The Serbia striker proved key to Madrid taming the high-pace attack of Sociedad in the 48th. After Vinicius passed to him in the box, Jovic quickly returned the ball for Vinicius to fire in his 10th goal, second in the league to Benzema's 12.
Jovic headed in his third goal for Madrid to secure the points in the 58th when he slid into position to push in a headed pass by Casemiro knocked on from a corner kick.
Sociedad, which was without playmakers David Silva and Mikel Merino, fell to fifth place after its first home loss.
Benzema's injury came before Madrid hosts Inter Milan on Tuesday to decide which wins their Champions League group. Madrid will then play Atletico next weekend.
The high point of the day for Barcelona's fans came before kickoff, when Barcelona player Alexia Putellas presented to the 65,000-plus fans her Ballon d'Or for the world's best women's player.
Otherwise, it was more frustration.
Juanmi Jimenez finished off a well-orchestrated counterattack to take Betis' winner with 11 minutes to play.
Barcelona had won twice and drawn once since Xavi replaced Ronald Koeman.
Betis' goal came just when Barcelona was playing at its best after Ousmane Dembele went on as a substitute for the final half hour.
Three times Dembele shot just by the post before Betis caught Barcelona on a three-versus-two breakaway.
Sergio Canales coolly drew in Barcelona's last two defenders and passed for Cristian Tello, who fed the now unmarked Juanmi to slot the ball past Marc-Andre ter Stegen.
``We have to stop those counterattacks,'' Xavi said. ``We had practiced just that, about when you have to make a tactical foul.''
Barcelona lost teen talent Gavi Paez in the first half following the powerful impact of a ball to his head. The club said Gavi was released from hospital after an examination.
Barcelona visits Bayern Munich on Wednesday needing a win to ensure its place in the Champions League round of 16. Bayern, which is already qualified as the group winner, beat Barcelona 3-0 in their first meeting this season.
If it loses, Barcelona would need Benfica to not beat Dynamo Kyiv to avoid elimination.
Atletico striker Cunha broke through for the defending champion in the 68th, only for Franco Russo to head Mallorca level in the 80th.
Atletico fell into the same trap that doomed Barcelona, pushing too many players forward in search of the winner. Take Kubo struck Mallorca's second goal in injury time after Angel Rodriguez launched him on a solo run from near the center line with a pass behind Atletico's defense.
Diego Simeone's side must win at Porto and hope AC Milan doesn't beat group winner Liverpool on Tuesday to reach the Champions League's knockout rounds.
Sevilla and Villareal also have key Champions League matches this week. Sevilla must win at Salzburg to move on, while Villarreal plays Atalanta needing a draw to advance.