Ilias kicked home a 22-metre winner at Accor Stadium on Saturday night, propelling Souths back into the NRL's top eight.
The kick came after Latrell Mitchell had a shot go wide of the mark late in regulation time, before another attempt from the fullback was scrapped after a poor pass around his feet.
But still, the Rabbitohs' success marked a far cry from several field goal situations last year in Ilias's first season in the NRL.
Souths failed to set up for a field goal in a loss to Wests Tigers last April, with forward Jai Arrow instead opting to take an ugly one-point attempt in the loss.
"We just had a better set up," Ilias said of Saturday night's decisive moment.
"Last year was pretty frantic and I think we just composed ourselves better this year.
"Trell was ready, I was ready. Everyone was on the same page."
Mitchell also missed the three shots in a golden-point loss to Cronulla late last season, with the Rabbitohs unable to find anyone else to take the kick.
But Ilias's kick on Saturday night should serve as a warning to rivals that the Rabbitohs now have two genuine options, with five-eighth Cody Walker not a noted drop-goal kicker.
"It's something we work on every week at training," Ilias said.
"Me and Trell always have some challenges against each other.
"I just told Cooky (Damien Cook) at the start of golden point, I will be ready. I know they will rush Trell.
"Cooky can pass it to either person. He can probably feel the markers edging towards Latrell's side. I'll be right side and he gave it to me."
Saturday night's win was an emotional one for Ilias and Souths, as the club honoured the life of John Sutton following his death at age 80 on Monday.
It was not lost on the halfback that the Rabbitohs' winning score was 13, the same number Sutton famously wore at the club.
Souths lock Cameron Murray also fought through 80 minutes in the No.13 jersey, as fans stood for an applause at the 13-minute mark.
"It meant a lot," Murray said.
"I didn't know John Sattler too well, but you know of him through all the stories people around the club talk about.
"As much as everyone talked about his toughness, they talked about how much of a good bloke he was off the field too.
"It just epitomises what it means to play at this club."
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