SCORERS: Rangers - Aird 22, Clark 52, Law 70, Crawford 90
Home manager Jim Jefferies had the hosts fired up from the off but any chance of an upset was killed off after 22 minutes when Aird put Ally McCoist’s side ahead.
And Dunfermline’s first defeat in nine games was confirmed with three goals after the interval as the Light Blues extended their lead over the Pars to 14 points with a game in hand.
Stripped of their 100 per cent record by a draw with Stranraer on Boxing Day, the Ibrox men made sure they resumed their canter towards the title with a much-improved display.
After sucking up some early Pars pressure, Rangers hit the home team with a sucker punch as Aird was allowed to advance before burying a low 20-yard strike.
They then doubled their lead six minutes after the restart as Clark pinched Jon Daly’s net-bound effort with a header from point-blank range. And on 70 minutes, substitute Lewis Macleod showed a sublime weight of pass as he rolled in Law for the third before Crawford rattled home a fourth in stoppage time.
With a crackle in the air created by the feisty 10,089-strong crowd, Dunfermline went in search of an early opening and thought they had one just four minutes in as Josh Falkingham sent Jordan Moore clear of the Rangers defence.
Bilel Mohsni and Sebastien Faure, however, recovered in time to crowd out the 19-year-old. At the other end, Steven Smith poked just wide of Ryan Scully’s left-hand post after Daly sent him into the Dunfermline box.
The opening stages of what would have been a top-flight fixture just a couple of seasons ago were marked by a series of meaty challenges, but referee Craig Charleston opted to keep things sensible by allowing play to flow as much as possible.
Dunfermline went close again on the quarter-hour mark as Stephen Husband met Alex Whittle’s near-post corner but saw his header saved by Cammy Bell.
Under pressure, the visitors survived another scare as Bell had to juggle Ryan Wallace’s shot from the left before finally grasping it safely.
Having themselves been under the cosh, Rangers were suddenly ahead as Aird drove into open space before finishing with a well-placed left-footed strike after Law did well to draw in three opponents before teeing up his team-mate.
Rangers were denied a second after 43 minutes as Scully blocked Daly’s shot from a Lee Wallace cut-back, while 90 seconds later home defender Lewis Martin had to hack clear from his own goal-line after Scully spilled Clark’s effort at the feet of Aird.
But McCoist’s men grabbed command of the game when Clark added the second. Aird swung in a corner from the right which Daly met at the near post and his header was destined for the net until Clark stole the credit for himself with a cheeky final touch on the goal-line.
And with 20 minutes left Ryan Williamson dallied on Young’s square pass and that handed Macleod the chance to steal before he measured a perfect through-ball for Law to prod beyond Scully.
Bell had to react smartly to deny Moore in the dying moments, but Rangers added a fourth in stoppage time as Crawford drilled home from 15 yards after Daly did well to set him up with a headed knock-down.
Dunfermline: Scully, Williamson (Spence 89), Young, Martin, Whittle, Geggan, Byrne (Smith 76), Husband, Falkingham, Wallace, Moore. Subs Not Used: Millen, El Bakhtaoui, Goodfellow, Kane, Dargo.
Rangers: Bell, Faure, McCulloch, Mohsni, Wallace, Black (Crawford 79),Aird, Law, Clark (Foster 69), Steven Smith (Macleod 57), Daly. Subs not used: Peralta, Simonsen, Emilson Cribari, Shiels.