Premier League leaders Chelsea equalled the top-flight record of 13 consecutive wins in a single season by beating valiant Stoke in a thriller at Stamford Bridge.
An exceptionally entertaining second half included five goals as the Blues were twice made to retake the lead by a Potters side who gave them one of their toughest tests this season.
Gary Cahill gave Chelsea the lead when he headed in shortly before half-time, but Stoke defender Bruno Martins Indi levelled only a minute after the break when he poked in from close range.
Willian handed the Blues the advantage again only for Peter Crouch to level with a side-foot effort high past Thibaut Courtois.
Stoke barely had time to celebrate, as moments after the restart Chelsea drove towards goal with Willian applying a fierce, angled finish.
With five minutes remaining, the Blues all but sealed the three points when Diego Costa shrugged off the attentions of Martins Indi to fire in the fourth.