Fresh from its penalty shootout victory over Atletico Madrid in the Supercopa de Espana, injury-hit Madrid was largely underwhelming until a moment of quality from Casemiro broke the deadlock shortly before the hour on Sunday (AEDT).
Indeed, Sevilla thought it had taken the lead through Luuk de Jong's header midway through the first half, but Julen Lopetegui's luck was out against his former club as VAR came to Los Blancos' rescue.
De Jong did have his goal when he curled in a superb strike from the edge of the area after 64 minutes, only for Casemiro to double his tally five minutes later as Madrid claimed the points.
After a promising run from Rodrygo Goes came to nothing, Toni Kroos had the first sighter of the match, curling a first-time effort tamely into the arms of Tomas Vaclik.
Madrid swiftly took control, but lacked cutting edge up top and relied on VAR to keep them on level terms with 30 minutes played when De Jong's header was disallowed for Nemanja Gudelj blocking off Eder Militao, much to Lopetegui's chagrin.
But Casemiro took matters into his own hands in the 57th minute, lifting a deft finish over Vaclik after racing onto Luka Jovic's clever flick.
Karim Benzema and Vinicius Jr were introduced as Zinedine Zidane looked to press home their advantage, yet it was Sevilla who struck next - De Jong's excellent finish into the left-hand corner allowed to stand despite an apparent handball from Munir El Haddadi.
Parity was short lived, however, and Casemiro made no mistake when he was left unmarked in the area to head home from Lucas Vazquez's cross, with a fine save from Vaclik preventing Kroos from adding a third late on.