The Belgian forward was in scintillating form as he netted his first treble in English football, taking advantage of slips by Arsenal and Manchester City to put his side first.
Jose Mourinho's men took advantage of Arsenal's 5-1 drubbing at the hands of Liverpool and Manchester City's goalless draw with Norwich City to leapfrog its title rivals.
Hazard was the hero, the 23-year-old producing a virtuoso performance and taking his goal tally for the season to 14 with an impressive treble. The Belgian opened the scoring midway through the first half with an emphatic finish and his second quickly followed as he rounded off a superb Chelsea breakaway after 34 minutes.
That ended the game as a contest but the former Lille man applied the gloss to a fine display with a penalty just after the hour mark.
Captain John Terry was left out for the Blues, who had the better of an open start to the game, Hazard's tame effort drawing a save from Tim Krul and Frank Lampard firing a free kick just wide.
Newcastle wasted a glaring chance just after the half-hour mark, Moussa Sissoko - captain in the absence of the injured Cheikh Tiote - denied by Cech following a superb through-ball from Davide Santon.
The visiting side was punished almost immediately as Hazard finished off a marvelous counterattack by surging into the box before playing a one-two with Samuel Eto'o and coolly slotting beyond Krul.
Mourinho's men continued to look fallible in defense and was grateful to Cech once more when the Czech goalkeeper scrambled to prevent Luuk de Jong from scoring on his full Newcastle debut with a close-range header.
Newcastle's problems mounted further five minutes before the halftime interval when Mathieu Debuchy limped off to be replaced by Mapou Yanga-Mbiwa.
Chelsea almost extended the lead in bizarre fashion early in the second half as Krul lost his footing in an attempt to claim David Luiz's long ball forward, which bounced over the Dutchman's head before eventually rolling wide of the goal despite Oscar's determined chase to keep the ball in play.
Mike Williamson prevented Eto'o from scoring a third with a fine block before Krul kept out a stinging free kick from Lampard.
However, the third goal finally arrived on 63 minutes, Hazard converting from the spot in confident fashion after Yanga-Mbiwa had hauled down Eto'o in the area.
The Belgian then came off to a rousing standing ovation prior to a flurry of late chances, Krul denying substitute Mohamed Salah a first goal for Chelsea before Sylvain Marveaux somehow shot wide following a Newcastle counter at the other end.