Chelsea were indebted to Kepa Arrizabalaga for a series of superb saves that preserved their lead after the break.
Maurizio Sarri, who reacted furiously when Kepa Arrizabalaga refused to be substituted, said the incident had been a "misunderstanding".
The fall-out from Maurizio Sarri's astonishing row with Kepa Arrizabalaga threatens to cause further damage in a crucial London derby against Tottenham.
Maurizio Sarri was visibly angry as Kepa Arrizabalaga refused to follow orders from the touchline.
Chelsea agreed to sell Belgian goalkeeper Thibaut Courtois to Real Madrid in a deal worth around 35 million euros.