Swansea's last-gasp 1-0 win at Millwall was held up for almost seven minutes after an allegation of racist abuse from the crowd towards Swans substitute Eom Ji-sung was reported by the Welsh club to officials.
Referee Edward Duckworth halted the match in the 65th minute and walked to the dug-outs to speak with Lions boss Alex Neil, Swans counterpart Vitor Matos and fourth official Ruebyn Ricardo. A security guard was also on the scene, with Duckworth seeming to point to an area in the stands behind the Swansea dug-out.
When play resumed, it was announced in the stadium that there had been a report of racist chanting, adding that police were working to identify any offenders using CCTV. Matos confirmed the player in question was South Korean winger Eom, who was warming up, and Neil said: "It's been reported and obviously it's not acceptable."
Millwall later released a statement which reads: "Millwall Football Club is aware of an alleged, individual incident of discriminatory abuse towards a Swansea City player during the second-half of Tuesday evening's Sky Bet Championship match. The club operates a zero-tolerance policy towards any form of discriminatory abuse. Any individual found to have engaged in such behaviour will face the strongest possible action. The club is working alongside the relevant authorities to establish the facts and is unable to comment further as tonight's alleged incident is the subject of an ongoing police investigation, which the club fully supports."
The incident could not take the gloss off a dramatic 1-0 victory for the table-toppers, courtesy of a winner at the death by substitute Ronald. Swansea arrived in south London with the best defensive record in the division and they showed why as Millwall dominated proceedings.
After the delay in play, Millwall searched for a winner and Lawrence Vigouroux made a point-blank save to deny Lyndon Dykes before Tristan Crama headed the resulting corner over. But Swansea nicked it at the death when Joseph Opoku crossed, Millwall hesitated and Brazilian winger Ronald, who had only been on the pitch five minutes, crashed home the winner.
"I think it was a lucky substitution by the manager," smiled Matos. "It was a really intense game, a good game, Millwall started really well. But I think we did it really well to deal with that, we stayed organised. That allowed us to grow into the game."
Neil, whose side could have climbed to fifth with a win, added: "I'm disappointed. I didn't think we deserved to lose. First half I thought we were the team looking threatening and they were under the cosh. But we didn't take our chances."