Simon, played by Nick Berry, missed the service itself due to his animosity with half-brother David - but fans saw him pay his own private tribute to his late mother in a special scene screened after the closing credits.
Secretly heading to Pat's grave in the dead of night, Simon laid down a bouquet of flowers as a mark of remembrance, before saying: "Goodbye mum."
Simon's return was a one-off cameo appearance and it is believed that show bosses only filmed the scene yesterday (Thursday).
The episode also saw the conclusion of Michael French's return stint as David, who fled the Square without Carol Jackson (Lindsey Coulson) - leaving her devastated.
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In the gallery below, Digital Spy takes an in-pictures look at Simon's EastEnders return.