Hearts retained their three-point lead over Rangers in the chase for Champions League qualification after a comprehensive demolition of the Pars.
Michal Pospisil (centre) scored for Hearts
Michal Pospisil scored from close range from a long throw and strike partner Roman Bednar headed the second.
Saulius Mikoliunas drove in the third from 16 yards after just 25 minutes.
Hearts took their foot off the gas after that, but Finnish striker Juho Makela headed a fourth before Dunfermline's Greg Ross was sent off.
Hearts head coach Valdas Ivanauskas had made four changes after the midweek defeat by Celtic.
Julien Brellier and Andy Webster were surprise omissions as Steven Pressley and Jose Goncalves returned from injury to pair up in central defence.
Hearts quickly adapted to the changes and a full house, as Tynecastle stadium was celebrating its 120th anniversary, watched them lay siege to the Dunfermline goal straight from the first whistle.
Deividas Cesnauskis drilled a 25-yard shot just past Allan McGregor's right-hand post after just 16 seconds.
Mikoliunas' right-footed effort from distance had the Pars goalkeeper diving to his right to pull off a fine save.
And Hearts took the lead after six minutes, when long throw from Robbie Neilson evaded McGregor inside the six-yard box.
And Pospisil, who had started in place of the injured Edgaras Jankauskas, had the easiest of tasks to knock the ball in from close range.
It was two after 14 minutes, Neilson crossing and Bednar looping a header over McGregor.
Then Mikoliunas picked up a Neilson pass inside the Fifers' penalty area and drove a decent angled shot from 16 yards that sped past McGregor for the third goal.
Only a good block by McGregor prevented Bednar scoring the fourth with a close-range volley.
Injury-hit Dunfermline had been forced to start without the influential Gary Mason in midfield, meaning a return for utility man Andy Tod.
And they had to wait until just before the break before testing goalkeeper Craig Gordon, who easily handled Mark Burchill's drive from distance.
An Aguiar drive from just inside the box shaved the base of the post as Hearts went for more goals after the break.
Tod headed just over following a corner as Dunfermline threatened to come back into the game.
But Hearts responded and Goncalves volleyed wide and McGregor saved well at the second attempt after Aguiar had been set up well by Cesnauskis.
And Makela scored his first goal for Hearts, heading in with eight minutes remaining, before Ross was red-carded for a late challenge.
Hearts: Gordon, Neilson, Pressley, Goncalves, Fyssas, Mikoliunas (Beslija 66), Aguiar, Hartley (Brellier 69), Cesnauskis, Bednar, Pospisil (Makela 58).
Subs Not Used: Banks, Webster, Tall, Driver.
Goals: Pospisil 7, Bednar 14, Mikoliunas 25, Makela 82.
Dunfermline: McGregor, Scott Wilson, Tod, Shields, Labonte, Thomson, McCunnie, Ross, Muirhead, Burchill (Phinn 88), Hunt (Tarachulski 66).
Subs Not Used: Halliwell, Iain Campbell, Daquin, Camano, Andy Campbell.
Sent Off: Ross (87).
Ref: C Richmond