The midfielder scored in stoppage time to salvage a point for United, after the hosts went ahead in the 87th minute through Jorginho's penalty.
Casemiro now joins an esteemed list of Brazilian Reds to have notched for the club, after becoming the tenth player from his homeland to represent United when he joined from Real Madrid in the summer.
Current Reds Fred and Antony also feature on the list, with the latter also achieving this feat just this season too.
Antony, who made the the move to United from Ajax in the summer, scored on his debut against Arsenal in September, before notching in his next two Premier League fixtures for the Reds.