The Brazilian has suffered mixed fortunes since arriving at the Emirates from London rivals Chelsea last summer and has often been on the receiving end of criticism for his performances this term.
Luiz temporarily silenced his critics following his dogged performance in Arsenal's FA Cup semi-final victory over Manchester City, but the 33-year-old made headlines for all the wrong reasons again on Sunday afternoon.
Arsenal stormed into a three-goal lead against the Hornets courtesy of a brace from Pierre-Emerick Aubameyang and a Kieran Tierney strike, but Watford were soon handed a lifeline as Luiz fouled Danny Welbeck inside the area.
Troy Deeney converted the spot kick before Welbeck's second-half goal gave Watford a glimmer of hope, but the Hornets ultimately fell to defeat at the Emirates and their relegation from the top tier was confirmed.
However, Luiz's blushes were not spared as the centre-back has now conceded more penalties in a Premier League season than any other player.
Luiz also conceded a spot kick in the reverse fixture with Watford in September, and the Brazil international also gave away penalties against Chelsea, Liverpool and Manchester City in the 2019-20 campaign. body check tags ::