The Spaniard was in the thick of the action at Stamford Bridge as he clashed with a number of Gunners players throughout his time on the pitch and played a huge role in the red card shown to Gabriel Paulista on the stroke of half-time.
Costa initially raised his hands into the face of Laurent Koscielny in the penalty area and then got into an altercation with Gabriel which resulted in the pair being booked.
As they continued their argument, the Brazilian defender was sent-off after appearing to kick Costa and that left Gunners boss Arsene Wenger incensed with the Blues striker after the game as he questioned how the defending Premier League champions were not also reduced to ten-men.
However, Mourinho stood by his striker when addressing the media in his post-match press conference and even went as far to suggest the 26-year-old was the best player on the pitch:
“I don’t have a view on the sending off. Man of the match for sure was Diego Costa. He brought everything to the game,” the Portuguese boss said [via Mirror Sport].
“Good victory, we need to win matches. We won twice in three days, we kept two clean sheets. We controlled the matches,” Mourinho added.
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