* Fabregas nets treble as Barca crush Mallorca * Ronaldo on target in Real's win against Levante * Rivals rest key men before European matches * Sociedad beat Malaga to strengthen grip on fourth (Adds Barca-Mallorca result, quotes) By Iain Rogers MADRID, April 6 (Reuters) - Cesc Fabregas and Alexis Sanchez were on scintillating form as leaders Barcelona made light of the absence of injured World Player of the Year Lionel Messi with a 5-0 win at home to Real Mallorca in La Liga on Saturday. ... More...