Chelsea defender Gary Cahill has labelled the challenge from Sergio Aguero that got the Manchester City striker sent off as "crazy".
Aguero was shown a straight red card for his stoppage-time foul on David Luiz, which sparked a brawl that also resulted in a red card for Fernandinho on Saturday.
Cahill was shocked by the severity of the Argentina international's challenge during Chelsea's 3-1 away victory but does not think that reflects his normal game.
"Maybe it was a bit of frustration," Cahill said to The Mirror.
"It was unlike him, it was out of character for him. It looked a bad tackle, out of character, it is disappointing to see that.
"They'd had a battle, him and David, and sometimes a bit of frustration spills over.
"It was a crazy tackle, not like him."
Chelsea now sit three points clear of Arsenal and four ahead of Liverpool and City at the top of the table, with Diego Costa joint-top of the league's goalscoring charts on 11.
Cahill was again impressed by the Spain striker, who scored the visitors' equaliser and produced an influential performance.
"I've seen more composure from him," said Cahill.
"I know everyone says he's an angry guy, but I'm seeing that composure now.
"I'm sure if you asked him, the first-half didn't go ideally. We were starved of the ball and so was he. He was scrapping around and not getting opportunities.
"In the last few years, maybe he gets frustrated at that point. But he kept his cool and got more involved in the second half.
"The players around him were playing well, defending for our lives when we didn't have the ball and he'll see that.
"He's one of the best going. There were two of the best on the pitch. He has been fantastic, showed maturity and he's banging goals in. He's on fire at the minute and we hope that continues."