Manchester City lost their cool in the dying minutes of Saturday's encounter with two of their players sent off.
City took the lead late in the first half, but second-half goals from Diego Costa, Willian and Eden Hazard gave Chelsea a smash-and-grab victory and the hosts lost their composure in stoppage time.
Sergio Aguero was sent off for a flying lunge on David Luiz and in the ensuing touchline melee, Fernandinho was dismissed after throttling Cesc Fabregas and shoving him over an advertising hoarding.
"It's a pity it finished like this. I don't like that. I apologise for what happened," said Guardiola, whose side have gone four home league games without victory.
Aguero now faces a four-match suspension, but Guardiola claimed his airborne foul on Luiz had not been intentional.
He also said Fernandinho, who will be banned for three games, had merely wanted to "defend his team-mate" when he confronted Fabregas, who played under Guardiola at Barcelona.
Asked for his verdict on Aguero's challenge, Chelsea defender Luiz told Sky Sports: "I don't like to speak about these type of things. Aguero is an amazing player who does a lot for football."
But he added: "We showed our power. It also shows our character that we didn't lose our heads."
It was Chelsea's eighth victory in succession -- their best such run within the same season since 2007 -- and left them four points clear of City at the top of the table.
Win number eight was a smash-and-grab effort, with City dominating the game and seeing Kevin De Bruyne hit the bar from five yards at 1-0 before Chelsea clinically picked them off on the break.
"I think today was very tough and the game was open until the end. There were lots of chances for both teams to score," said Chelsea manager Antonio Conte.
"I saw lots of character from my team and that's very important to grow. But we must continue to work and improve."
City defender John Stones, whose side went ahead courtesy of Gary Cahill's own goal, said: "There is quite a sour feeling running through everyone's mind. It is a difficult one to take in the end.
"The scoreline didn't reflect the way we played. In my opinion we should have won 3-1. But that's football."