Chelsea eased to a comfortable 2-0 win over Watford at Stamford Bridge to restore their two-point lead over Manchester United.
Olivier Giroud opened the scoring with an instinctive finish into the far bottom corner in the 28th minute.
Willian scored his fourth goal in three appearances from the spot just before the break, after Etienne Capoue recklessly upended Christian Pulisic inside the box.
Ross Barkley completed a comfortable victory for Chelsea by caressing an unerring finish past Ben Foster in second half stoppage time.
Chelsea set the tone during the opening exchanges by dominating possession and forcing Watford into a defensive formation. The Hornets played with a 4-5-1 formation with both full-backs showing little intention of advancing forward and joining the attack.
Troy Deeney often looked isolated as the solo striker and Chelsea looked to unlock the defence with the creative quality of Mason Mount and driving runs from Pulisic.
Giroud came close to breaking the deadlock when his low strike was thwarted by the trailing leg of Ben Foster. Watford failed to contain the Frenchman once again and Giroud ruthlessly punished them with a clinical finish into the far bottom corner.
Mount swept the ball into Barkley and the England international immediately swivelled into space and weaved an inviting through ball into Giroud. Craig Dawson attempted to make a last-ditch block but Giroud expertly found the bottom corner with an instinctive finish.
Watford defended with discipline and organisation during the closing stages of the first half until Capoue stormed into a reckless challenge on Pulisic. The Frenchman brainlessly charged into the United States international and left Nigel Pearson absolutely speechless on the touchline.
Willian calmly slotted his penalty into the bottom corner, sending Foster the wrong way, to notch his 11th goal of the season in all competitions.
Watford failed to respond after the break and the start of the second half took on a very similar pattern to the first. Chelsea dominated the ball in the heart of midfield and Pulisic and Mount combined effectively in the final third.
Pearson responded by introducing Tom Cleverley and Danny Welbeck but Watford still struggled to breach the Chelsea defence. Welbeck was denied by the outstretched arm of Kepa and Will Hughes missed a gilt-edged chance after Welbeck made a mesmerising run and squared the ball at the by-line.
Chelsea also had chances to extend their lead but Foster denied Willian from range and gathered Kurt Zouma’s header from the resulting corner.
The Blues sealed all three points when Cesar Azpilicueta drilled a low cross into Barkley for the Englishman to fire his finish past Foster who was rooted to the spot.
Chelsea: Kepa; R James, A Christensen, K Zouma, C Azpilicueta; N Kante (B Gilmour 78′), M Mount (R Loftus-Cheek 76′), R Barkley; Willian (C Hudson-Odoi 76′), O Giroud (T Abraham 76′), C Pulisic.
Subs not used: W Caballero, A Rudiger, M Alonso, Jorginho, T Abraham, Pedro, R Loftus-Cheek, C Hudson-Odoi, B Gilmour.
Watford: B Foster; A Mariappa, C Kabasele, C Dawson, K Femenia (A Masina 64′); N Chalobah, E Capoue (D Welbeck 58′); I Sarr, A Doucoure, W Hughes; T Deeney (T Cleverley 64′).
Subs not used: H Gomes, C Cathcart, J Pedro, A Gray, J Holebas, R Pereyra.