Sergio Aguero was sent off for a horrific stoppage-time tackle on Chelsea star David Luiz as Manchester City were beaten 3-1 by the Premier League leaders on Saturday.
The pair have history, with Aguero having sparked a furore with a two-footed challenge on the Brazilian in the 2013 FA Cup semi-final, for which he managed to avoid further punishment.
But which other players appear to hold a grudge? Here, Sportsmail looks at the hot-headed rivalries which have occurred on the football pitch.
Diego Costa vs Gabriel
Although Diego Costa appears to have turned a corner this season with his antics, it's perhaps no surprise to see the Brazilian-born Spain international make this list.