West Brom ended Norwich City's 10-game unbeaten record in the Barclays Premier League with a late 2-1 win at The Hawthorns.
Robert Snodgrass gave the Canaries an early lead after fit again Baggies keeper Ben Foster failed to keep out his dipping free-kick.
But Zoltan Gera ended West Brom's near six hour goal drought just before the break and then on-loan Chelsea player Lukaku headed the winner with eight minutes remaining to leave Baggies boss Steve Clarke hoping the Blues do not decide to recall their player during the January transfer window.
Victory ended Albion's mini slump from which they had collected only two points from four games after climbing to third spot.
They deserved their success after looking the more threatening during the second period.
But Albion were also indebted to another rock solid display from central defender Gareth McAuley. The Canaries came close to a share of the spoils despite the absence of key striker Grant Holt with a hamstring injury.
In addition to his goal, Snodgrass was always asking problems of the Albion defence
Lukaku came close to opening the scoring for the Baggies after three minutes.
The striker made good contact on his glancing header from Goran Popov's deep cross but it flew just over the bar. Snodgrass connected with a volley from the edge of the Albion box but it was directed straight at Foster who returned after a seven game absence through injury.
The first clearcut opening fell to Lukaku after 21 minutes when he took a pass from James Morrison in his stride. But Lukaku failed to make a clean contact on his cross shot and Mark Bunn saved with relative comfort.
It proved a costly miss as Snodgrass put the Canaries ahead three minutes later after Peter Odemwingie brought down the midfielder.
His curling free-kick contained plenty of power and, although Foster got a hand to the ball, he could only help it into the roof of the net.
The shake of the head from the former England international conveyed the impression he should have done better. West Brom tried to retaliate and a goal-bound effort from McAuley was blocked by the body of Bunn following a Chris Brunt corner.
But after 43 minutes Gera brought Albion back on level terms with his fourth goal of the campaign. Bunn parried Jonas Olsson's downward header from a Brunt corner onto the crossbar but Gera was on hand to volley home the rebound.
Clarke replaced Graham Dorrans with Marc-Antoine Fortune for the second period.
McAuley rescued Albion with a superb tackle inside the box after Steve Morison took advantage of a mix-up at a short free-kick by the home side.
Norwich centre-back Michael Turner headed wide from Snodgrass' centre before being booked for hauling down Odemwingie in full flight.
Odemwingie had a low shot saved at the base of a post by Bunn but chances were now at a premium. Clarke brought on West Brom top scorer Shane Long - in place of Gera - in a bid to add more fire-power.
Then with eight minutes left Lukaku showed his power and strength when climbing above Javier Garrido to head home Popov's deep cross.
Popov was booked in injury time for a foul on Snodgrass but Albion held on to claim their seventh home win of the season.
