Andy (played by Oliver Farnworth) was trying to find evidence to prove that Phelan was guilty of the building scam, Michael's murder and forcing him to burn down Kevin's garage.
But, he was interrupted by the builder who stormed into the flat to stop Andy from revealing the truth. As he confessed to everything, Andy recorded their conversation on his phone.
Unfortunately, Phelan realised what he was doing and quickly pinned him against the wall and tried to retrieve the mobile.
He warned Andy that he could kill him but had decided to let him leave for Portugal with his girlfriend Steph.
Phelan went round to Andy's to check he was really leaving the street
Phelan attacked Andy when he realised he was recording his confession about the building scam
However, Andy picked up his laptop and lashed out at Phelan. But the villain hit back and the two became embroiled in a fight.
The scuffle ended when Phelan picked up the computer and hit Andy over the head, brutally murdering him.
Oliver was aware that his character would be departing the soap but bosses managed to keep his death under wraps.
Speaking about his final scene, the actor told Digital Spy: "It was bittersweet, because as much as no one likes to leave any lovely job with amazing people, when the story lines were pitched to me I thought, 'What a great challenge, what a way to go'."
Phelan knocked Andy against the wall as he struggled to take the phone
Coronation Street's most dramatic moments
Thu, January 12, 2017
Coronation Street's most dramatic moments.
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Michelle Connor suffered a heartbreaking miscarriage
Phelan killed Andy by hitting him over the head with his laptop
He added that he felt "honoured" to be Phelan's first real victim on the soap, explaining: "Obviously Michael was Phelan's first victim inadvertently as far as the fact that he didn't help him, he left him there!
"So Andy goes up against him to avenge Michael's death and he does his best, he tries! But I feel honoured to be on the list of Phelan's victims and one of his first!"
Coronation Street continues on Monday on ITV at 7.30pm.