Vinicius Junior opened the scoring.
Benzema helped himself to a double after Vinicius Junior had opened the scoring as the leaders increased their advantage over second-placed Sevilla to double figures, with arch-rivals Barcelona a further five points behind.
The Frenchman, whose hat-trick against Paris St Germain last Wednesday evening secured Madrid’s passage to the Champions League quarter-finals, was denied by keeper Sergio Rico early on, while Vedat Muriqi and Takefusa Kubo both went close for the home side inside the opening 18 minutes.
Toni Kroos gave Rico something to think about from distance with 28 minutes gone, but it was Mallorca who were denied the lead when Pablo Maffeo’s shot came back off the upright seven minutes later.
Vinicius finally made the breakthrough 10 minutes after the restart when he converted Benzema’s pass to put the visitors ahead, and he was instrumental as his side increased their lead 13 minutes from time.
The Brazilian was fouled by Brian Olivan inside the penalty area and Benzema stepped up to convert the spot-kick, and the Frenchman doubled his tally with an 82nd-minute header.
In Italy, Ciro Immobile’s penalty was enough to ease Lazio into fifth place in Serie A with a hard-fought 1-0 home win over lowly Venezia.
Sergej Milinkovic-Savic went close to opening the scoring for the home side with a 15th-minute free-kick which flew just wide and Felipe Anderson missed the target from a tight angle 11 minutes before the break, but the sides headed for the dressing rooms with the deadlock unbroken.
Lazio finally took the lead 13 minutes into the second half when, after Luiz Felipe had been fouled by Domen Crnigoj inside the box, Immobile dispatched the resulting penalty and that proved decisive.