Andy Carroll scored at Anfield for the first time this season to help Liverpool reach the fourth round of the FA Cup with a 5-1 win over League 1 (third division) Oldham Athletic on Friday.
England international Carroll, bought for 35 million pounds ($53.93 million) from Newcastle United last January, pounced with injury time approaching to put Liverpool 4-1 up after they had gone behind in the 28th minute.
Oldham's Robbie Simpson produced an unstoppable strike from 25 metres in the 28th minute but Liverpool quickly drew level when a Jonjo Shelvey shot destined for the goalkeeper's hands deflected off Craig Bellamy into the corner of the net.
Liverpool captain Steven Gerrard, plagued by injuries in 2011, then rifled home a penalty at the end of the first half to give his side a 2-1 lead.
Bellamy's pace unsettled Oldham as Liverpool made it 3-1 after 68 minutes, the Welsh winger's cross after a dashing run dispatched by Shelvey.
Misfiring striker Carroll then grabbed his third goal of the season after a swivel on the edge of the box and a smart finish before Stewart Downing made it 5-1 deep into injury time.
"Downing scored, big Andy got a goal, Jonjo scored and Steven scored with a penalty so we've had a few positives but I don't think the scoreline reflects the distance between the two teams on that performance," said Liverpool boss Kenny Dalglish.
However, the game ended on a sour note when Oldham's Tom Adeyemi exchanged words with a spectator and the tearful midfielder needed a consoling word from Gerrard.
Liverpool issued a statement saying: "An incident occurred in the second half of the match which is now being investigated by both the club and the police."
Merseyside Police added: "The aim of the investigation is to establish the full circumstances surrounding the incident to ascertain if action needs to be taken."
"(We) can confirm that no one has been arrested this evening... on suspicion of racially aggravated behaviour during tonight's FA Cup fixture at Anfield," said a police spokesman.
The main programme of third-round ties will be on Saturday but the highlight is holders Manchester City's home game with Manchester United on Sunday (1300 GMT).