The Blues took the lead at Anfield in the opening period as Kai Havertz looped a header over Alisson from a Reece James corner. That goal appeared to be sending Chelsea into the half-time interval ahead. Yet just before the break, chaos ensued.
A Liverpool corner was delivered deep by Trent Alexander-Arnold and Chelsea struggled to get the ball clear. In the scramble, a shot bounced off the knee and onto the arm of James as he tried to clear.
VAR called for a review and referee Anthony Taylor showed no hesitation in sending off James and awarding a spot kick, which was converted by Mohamed Salah.
The second period was very much a case of attack against defence. For 45 minutes, Chelsea repelled wave after wave of Liverpool pressure. And it was enough to get them over the line.