The There Will Be Blood star joined fellow celebrities Kevin Spacey, Julie Walters and Michael Gambon at a church service on Wednesday (16Feb11) in memory of The Usual Suspects actor, who died on 2 January (11) after a long illness.
Day-Lewis, who appeared alongside his pal "Pos" in 1993 drama In the Name of the Father and 1992's The Last of the Mohicans, led the heartfelt speeches by recalling their time together at the Old Vic Theatre School in Bristol, England, where they trained together early on in their careers. He then sang to Postlethwaite's grieving widow, Jacqui.
In a heartfelt tribute to the actor shortly after his death last month (Jan11), Day-Lewis revealed he grew up wanting to be just like the 64 year old.
He said, "As students, it was him we went to see on stage time and time again. It was him we wanted to be like; wild and true; lion hearted; unselfconscious, irreverent. He was on our side. He watched out for us. We loved him and followed him like happy children, never a breath away from laughter. He shouldn't have gone."