West Brom maintained their push for a European spot but needed an own goal from Swansea midfielder Jonathan de Guzman to seal a 2-1 victory over Swansea in the Barclays Premier League clash at the Hawthorns.
Capital One Cup winners Swansea started in impressive style and deserved to go ahead through former West Brom striker Luke Moore's header. Lukaku equalised with his 13th goal of the campaign before the decider from De Guzman but the visitors had a late effort from substitute Roland Lamah harshly ruled out for offside.
Lukaku could afford the luxury of having a penalty saved by Swans keeper Michel Vorm when the score was 1-1 as Albion secured their third win in the last four games. Even Lukaku was eclipsed by another excellent performance in the centre of the park by James Morrison.
Michu missed an early opportunity to break the deadlock as Pablo Hernandez's right-wing cross dropped invitingly for Swansea's 19-goal leading scorer inside the danger area but he sent his shot over the bar.
Albion right-back Billy Jones brought down Wayne Routledge 20 yards out but De Guzman curled his free-kick past the post. Good link-up play by Hernandez and Luke Moore then carved another opening for Michu but he stabbed his shot wide.
Moore celebrated his first start since Boxing Day by opening the scoring against his former club. He got in front of his marker to glance his header from De Guzman's corner past Ben Foster into the far corner of the net.
But Albion hit back and Lukaku levelled after 40 minutes with his 13th goal of the campaign. Dorrans threaded a low ball towards the near post and Lukaku was first to react in steering the ball past Michel Vorm.
Albion were awarded a 56th-minute penalty for a challenge on Morrison by Routledge just inside the box. Up stepped Lukaku to take the spot-kick but Vorm was equal to his low drive away to his right and was able to save.
The Baggies were not to be denied and an own goal from De Guzman put them ahead four minutes later. Gareth McAuley's header from a Brunt corner was cleared off the line by Angel Rangel but rebounded back off De Guzman into the net.
Swansea substitute Roland Lamah had the ball in the net in the 87th minute, but it was ruled out for offside although the ball appeared to hit home defender Gareth McAuley before rebounding into his path.