Los Blancos usurped Barcelona’s record of 18 by winning 4-0 at home to Ludogorets.
Brazilian defender Marcelinho’s red card for handball gifted Cristiano Ronaldo the opener from the penalty spot, allowing the superstar to surpass Raul’s Champions League goals haul with his 72nd strike.
Ronaldo still trails Lionel Messi, who recently eclipsed Raul with a hat trick last month to give him 74 Champions League goals.
Real Madrid, who had already won Group B and advanced to the knockout stage, stretched equalled their 100 percent group-stage record achieved under Jose Mourinho in 2012.
Real Madrid have outscored their opponents 71-9 during their winning streak, which consists of six Champions League matches, 11 in La Liga, and two in the Copa del Rey.
Barcelona had won 18 straight in the 2005-06 season under Frank Rijkaard.
They became the first club in Champions League history to win all their group matches on two occasions with the 10-time champions previously achieved the feat in the 2011/12 season according to UEFA.