Chelsea’s very expensive German strikers finally joined the Premier League goal frenzy but a late header by Jan Vestergaard denied them victory.
Vestergaard struck in stoppage time, a glancing header to divert a volley by Theo Walcott past Kepa Arrizabalaga as Southampton fought back to rescue a point.
Frank Lampard’s team were two goals up through Time Werner but their continuing frailties in defence allowed Saints back into the contest.
Danny Ings and Che Adams hauled the visitors level before Kai Havertz struck what appeared likely to prove the winner at Stamford Bridge.