Chelsea won back-to-back Premier League games under Frank Lampard for the first time with a 4-1 win at Southampton.
Tammy Abraham's eighth league goal of the season set the Blues on their way after 17 minutes before Mason Mount doubled the lead. Danny Ings' effort on 30 minutes gave Southampton hope but N'Golo Kante's deflected effort before half-time gave the visitors breathing space again.
Christian Pulisic, on as a substitute, found Michy Batshuayi in the 89th minute and he made no mistake to complete the rout.
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Victory at St Mary's moved Lampard's men up to fourth, with struggling Southampton still just a point above the bottom three.
Chelsea looked a little lethargic in the opening stages and were fortunate not to go behind inside the first minute as Nathan Redmond's fierce drive just whistled over the bar.
Abraham then tested Angus Gunn with a low shot before getting the better of him following a good pass from Callum Hudson-Odoi. Abraham took a neat touch and lofted the ball over the onrushing goalkeeper and despite Maya Yoshida's attempts to clear, goalline technology proved the ball crossed the line.
Southampton were reeling and just seven minutes later, Mount grabbed his fourth of the season following a slick move. Willian pounced on poor defending and the ball eventually found Mount, who slammed past Gunn to put Chelsea in charge.
Mount should have made it 3-0 but screwed wide soon after and he and Chelsea were made to pay when Ings diverted a cross from the right in to reduce the deficit.
Southampton looked invigorated following Ings' strike but were left deflated just before half time when Kante's effort deflected past Gunn to restore Chelsea's two-goal advantage.
Hudson-Odoi almost made it 4-1 just after the break but Gunn stood firm to deny him and Chelsea closed the game out with relative ease to claim a fourth win in a row in all competitions, with Batshuayi finishing things off late on.