The Real Madrid captain went into the game against PSG on Tuesday night level on cards with former Manchester United midfielder Paul Scholes on 36 in the competition.
As the game wore on though, the inevitable 37th soon came, with the former Sevilla man sliding in from behind on substitute Javier Pastore to take him to within a booking of what could be a costly suspension.
Ramos' tally of 37 cards, including three reds, stands unchallenged as the highest total of any player in the competition.
However, his presence at the top of the disciplinary charts should come as little surprise, with the 31-year-old having recently officially become the most booked player in La Liga history.
6 March 2018