Coach Carlo Ancelotti took a calculated risk to rest Benzema for the game at Estadio Manuel Martinez Valero, and his side got the job done to move level with leader Real Sociedad, which plays Athletic Bilbao on Monday (AEDT).
Vinicius swept a delightful opener past former Madrid man Kiko Casilla with 22 minutes played, and Elche's task was made all the more difficult when Raul Guti was dismissed shortly after the hour mark.
Brazil international Vinicius doubled his tally 17 minutes from time and, despite a late consolation for substitute Pere Milla, Madrid saw the game through to get back to winning ways on the back of its midweek stalemate against Osasuna.
Rodrygo and Mariano were surprisingly selected in Madrid's frontline, with the likes of Eden Hazard, Luka Jovic, Isco and Marco Asensio among the substitutes.
But Madrid was forced into an early change when the injured Rodrygo was replaced by Asensio, and it would have been behind a minute later if not for a good Thibaut Courtois save to keep out Lucas Boye's powerful strike.
Elche edged the first-half chances but fell behind to Vinicius's eighth goal in all competitions this term, as he fired across Casilla after being played in by a sublime back-heeled flick from Mariano on his first appearance of the season.
The hosts continued to look a threat as Lucas Perez somehow fired wide with plenty of the goal to aim for and Guti blasted a volley straight at Courtois.
That momentum was halted when Guti was issued a second yellow card for sliding in on Toni Kroos, however, and Vinicius made Elche pay with a chipped finish over Casilla from an acute angle.
A Casemiro error gifted Milla the chance to pull one back just five minutes after being introduced, though that proved to be nothing more than a consolation for the home team.