The Brazilian-born striker kept his cool to show off his class as the Blues impressively came from behind to beat Manchester City 3-1 in a fiery encounter and open up a four-point gap to their title rivals.
Costa has often been troubled by disciplinary problems, but 11 goals and five assists this season have been crucial to the club’s resurgence after a disappointing 10th place finish last term. Noticeably, he acted as a peacemaker when a massive brawl broke out after City’s Sergio Aguero had caught David Luiz with a wild injury-time challenge.
The Argentine striker was sent off, along with Fernandinho, who grabbed Cesc Fabregas by the throat in an ugly exchange.
“It was unlike him, out of character for him,” said Cahill on Aguero’s red rage. “They’d had a battle, him and David, and sometimes a bit of frustration spills over. It was a crazy tackle, not like him.”
It was something more expected of Costa than Aguero, but he’s a changed man as Cahill added: “I’ve seen more composure from him. I know everyone says he’s an angry guy, but I’m seeing that composure now.
Diego Costa: "Did someone say there's a fight?" pic.twitter.com/3GNAU9yurp
— Football Fights (@footbalIfights) December 3, 2016
“The first half didn’t go ideal for him. 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. He’s one of the best going. They were two of the best on the pitch (Costa and Aguero), but he’s been fantastic, showed maturity and he’s banging goals in. He’s on fire at the minute and hope that continues.”
Chelsea are also on fire with eight successive wins and Cahill says they are thriving under pressure as they become a team to fear again.
“I hope so,” he added. “But we are not even at Christmas yet so I don’t want to talk too much, but at the same time I’m sure teams don’t want to play against us. They were on top and 1-0 up, but it never really rocked us too much mentally and we came out for the second half and played well.
“We’re in a good place and we’re on a good run. A lot is made of the big games that are on TV and every week at the moment we seem to be on TV and every week there is a demand to win games and the pressure is there. Every time we go out it’s a case of ‘we can’t lose’, but I think it’s a good pressure to have on ourselves. We have to keep that momentum going.
“Last year was a blip since I’ve been part of the club and every year apart from that we have won something or been competing so I suppose we are back to a bit of normality at the top of the table again.”
The fact Chelsea have had a settled side has helped, adds Cahill. They have made just eight changes to City’s 46 and Pep Guardiola’s defence has struggled with changing personnel and systems.
“In the boxes we are not strong enough,” said the City boss. “But I don’t think we lost because of the defensive problems.
“Always in my career we conceded few goals because we dominated through ball possession and created chances to be far away from that. When we play better and better and better we will concede few chances and will score more goals.”
City and Chelsea will also await the findings of referee Anthony Taylor’s report as they could face Football Association charges for failing to control their players. Fernandinho could also be punished for pushing Fabregas over an advertising hoarding while the Spaniard appeared to slap the City midfielder.
Fabregas was booked, as was Nathaniel Chalobah, in the melee, but retrospective action could still be taken.
