Fluminense defender Gum scored a last-minute own goal to hand local rivals Flamengo a dramatic 1-0 victory in the Campeonato Brasileiro football league.
The reigning champions looked set to salvage a draw at the Maracana stadium before Gum slid an injury-time cross from Rafinha into his own net, reports Xinhua.
The result places further pressure on Fluminense coach Vanderlei Luxemburgo, whose future at the club has been under scrutiny in recent weeks.
Flamengo are now 10th in the standings with 44 points from 32 matches while Fluminense are 16th - one spot ahead of the relegation zone - with 36 points.
In other matches Sunday, Goias defeated Botafogo 1-0, Vitoria and Corinthians drew 1-1, Bahia held Gremio 1-1, Atletico Paranaense beat Internacional 1-0 and Criciuma drew 1-1 with Ponte Preta.