Viewers saw his character Phil Mitchell coming to terms with his mother Peggy's suicide, after she ended her life earlier in the week, having been battling terminal cancer.
They were reduced to tears during one particular scene, which saw Phil reading a note Peggy had left him before she died.
Barbara Winsdor, who bowed out as the Walford matriarch during Tuesday's episode, could be heard reading out the heartbreaking goodbye message, which tried to help her son come to terms with her decision to end her life.
My darling Phil. I’m writing your letter last - because it’s the hardest. You’re probably angry with me. Try not to stay angry. This isn't what you wanted, but one day I hope you’ll accept my decision. I only have one regret: I should never have asked you to help me. It was selfish. I was scared. I was worried about being alone. But I’m not scared now. And I’m not alone. And neither are you. Phil, you’re surrounded by people who love you. Just try to love yourself as much as they do, as much as I did. Because I always loved you - from the moment I first held you in my arms. My gorgeous boy. My first, best, boy. Peggy Mitchell
Instead of the usual 'doof doofs', the episode then ended with a moving version of the show's iconic music, entitled 'Peggy's Theme', which was created when the character first left the show in 2010.
The combination of hearing the late Peggy's voice, Steve's highly charged performance and the sad theme tune left fans a wreck:
Others also called for Steve to be rewarded for his portrayal of Phil at this year's British Soap Awards:
There is still plenty of heartache left to come for the Mitchell family, with Peggy's funeral set to air in the coming weeks.
It will also mark the return of Danniella Westbrook as Peggy's daughter Sam.
'EastEnders' continues tonight at 8pm on BBC One.
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