With erstwhile leaders Arsenal sinking to a miserable 5-1 loss at Liverpool and City held 0-0 at Norwich, Chelsea moved a point clear at the top courtesy of a 3-0 win over Newcastle at Stamford Bridge.
Away from the title battle, the action was just as heated at the foot of the table with Crystal Palace, West Ham and Hull each claiming key wins in their fight to beat the drop.
Palace ran out 3-1 winners at home to West Brom, who now find themselves inside the bottom three.
Tom Ince, signed from Blackpool on deadline day, marked his Eagles bow with a goal after 15 minutes, while Joe Ledley, freshly arrived from Celtic, made it two just before the half hour.
Hull wrapped up a double over Sunderland as goals from new boys Shane Long and Nikica Jelavic saw them to a 2-0 win at the Stadium of Light.
In the day's other game at St Mary's, Southampton and Stoke fought out a 2-2 draw.