Some have predicted Fulham will struggle this season, particularly if they lose Dempsey to Liverpool, but if this display is anything to go by, Fulham will not miss their 23-goal talisman from last season one bit.
The Cottagers put on a sublime display to tear Norwich apart and demoralise the Canaries fans who had travelled to south-west London hoping to see Chris Hughton win his first match in charge of the Norfolk club.
Petric, signed on a free transfer from Hamburg this summer, was the star of the show, scoring twice after Damien Duff had poked home a brilliant pass from John Arne Riise to open the scoring.
Alex Kacaniklic, chosen to play in Dempsey's position, scored his first Fulham goal to make it 4-0 and substitute Steve Sidwell blasted home a penalty four minutes from the death to seal the rout.
Norwich looked a shadow of the team that finished 12th under Paul Lambert last year, and had it not been for a good performance from John Ruddy, the Canaries could well have conceded seven or eight.
A Fulham victory looked on the cards from the off. The home side started confidently, with Kacaniklic and Bryan Ruiz both swinging in dangerous crosses that just evaded Petric.
Brede Hangeland sent a raking ball over the Norwich defence to find Duff, but Michael Turner came to the Canaries' rescue by nudging the winger out wide.
Norwich raced up the other end and forced Mark Schwarzer into a save when Andrew Surman fired at goal, but that proved to be the visitors' only chance of the first half as Fulham dominated.
Ruddy's awful clearance landed straight at the feet of Ruiz, but the Costa Rican cleared the bar while the Canaries stopper raced back to his line.
Ruddy made amends by saving well from Riise and Petric, but the Norwich goalkeeper was beaten soon after by Duff's opener.
Riise hit a delightful cross-field pass to find the former Blackburn man and his shot trickled in off Ruddy's outstretched leg.
Fulham almost added a second when Petric found Ruiz in the box but Ryan Bennett raced across the back four to put in a crucial tackle.
The Cottagers had their second from the resulting corner, however, as Petric glanced home Duff's cross in. Jonathan Howson hooked the ball clear, but the linesman correctly ruled it had already crossed the line.
Ruddy pulled off a terrific flying save to deny Ruiz just before half-time as Fulham threatened to run riot.
Hughton brought on Steve Morison for Andrew Surman and switched to 4-4-2, but Norwich were still by far the worst team on the pitch.
Eight minutes into the second half Fulham scored their third.
Ruiz found Petric in space and the Croatian fired home a 30-yard shot that took a wicked deflection off Turner.
Thirteen minutes later it was 4-0. Petric backheeled into the path of Kacaniklic from a Mousa Dembele pass and the 21-year-old finished calmly.
The backheel proved to be Petric's last contribution to the game as he was substituted for fellow debutant Hugo Rodallega.
Bradley Johnson found space on the edge of the Fulham box and forced Schwarzer into a rare save, but the home side hit back and were not willing to settle for four.
Kacaniklic lost his marker after drifting in from the flank and fired a powerful shot that Ruddy did well to save.
Four minutes from the end Fulham were gifted another goal when Turner's awful tackle on Rodallega earned the London club a penalty and Sidwell hammered the spot-kick into the roof of the net.
"Are you watching Clint Dempsey?" echoed around Craven Cottage in the closing stages, the home fans clearly delighted that they had opened their season with an emphatic victory without their leading talisman.