If Real Madrid end the season as LaLiga champions, they may well look back on this win over Sevilla – and the performance of Casemiro – as a defining moment.

This was a game that had the hallmarks of a setback for Zinedine Zidane. Okay, Madrid had beaten Sevilla in 10 consecutive league games in the capital going into this meeting, but Julen Lopetegui has created an obstinacy about the Andalusians that had restricted them to just three away defeats in all competitions this term.

Consider, too, that Madrid went to penalties in the Supercopa de Espana final six days ago before the long flight back from Jeddah. They also started this game without a sizeable host of first-team stars: captain Sergio Ramos was out with a sprained ankle, Eden Hazard, James Rodriguez and Gareth Bale were not in the squad, Federico Valverde was banned and Karim Benzema only able to start on the bench.

Still, one thing about the modern Madrid is that they generally perform to a far higher standard when Casemiro is on the pitch, so maybe this kind of match-winning display was bound to happen eventually. Few would have seen this coming, though.

Zidane has made Madrid extremely tough to score against in recent weeks. They had kept five clean sheets in nine games before Sevilla's visit and conceded only 12 goals in LaLiga all season, a record only matched by, of course, Atletico Madrid.

But they found themselves in trouble on Saturday. Without Ramos to dictate terms from the back, Sevilla's high press had them worried; with a depleted attack, chances of their own were scarce. Luuk de Jong thought he had buried the opening goal just before the half-hour mark only for VAR to intervene and penalise Nemanja Gudelj for blocking Eder Militao.

Amid the uncertainty of their wider display, Casemiro was doing as expected. He made five tackles and won possession 11 times in the match, more than any other player on the pitch, and only Diego Carlos bettered his tally of two interceptions.

Then came the surprise. With 57 minutes gone, Luka Jovic played an inspired backheel into Casemiro's path, he muscled his way through the Sevilla box and chipped an impudent effort beyond Tomas Vaclik. It was a striker's finish, oozing calm and precision – two qualities not always associated with one of Madrid's more ebullient characters.

Twelve minutes later, it happened again.

De Jong had equalised with a finish of the highest quality – a rare incident this season. Five minutes on, Lucas Vazquez sent in a cross and the unmarked Casemiro rose highest and nodded home his second goal of the game. Even rarer.

Casemiro had never scored twice in a Madrid match before and he cannot have ended many games with no team-mate having attempted more shots. Indeed, he could have had a hat-trick but for a miscued effort in the closing stages.

Casemiro is hardly an unsung hero at the Santiago Bernabeu, but this was a rescue act in a very different guise, his impact in the opponent's box even more important than his tigerish efforts in defending his own.

It means Madrid are unbeaten in 17 games in all competitions and return to the top of the table ahead of Barcelona's game against Granada on Sunday. With their form showing few signs of dipping and with stars aplenty to return, this might prove to be Casemiro's most decisive performance yet.