The German beat home favourite Caleb Ewan (Mitchelton-Scott) and world champion Peter Sagan (Bora-Hansgrohe) in a straightforward sprint to take line honours at the end of the 145km race to Lyndoch.
Greipel lost his mother, Gudrun, 57, to ALS last year, which some of his Lotto-Soudal team staff partly attributed to an uncharacteristic dry run at the Tour de France.
The 35-year-old never used the deep loss as an explanation for his performance there and didn’t need to in Adelaide where he was clearly back to his best.
Greipel when asked post-race if he’d dedicate the stage victory to his mother, openly went one further.
“I think my whole career is dedicated to her,” he said.
“She was my biggest supporter, all my career, and I know she keeps looking.
“It wasn’t the easiest off-season … but I have to look to the future.
“We have a lot of support from around the family, around the team. It wasn’t easy to deal with, and still isn’t, but the sport helps me to deal with everything.”
Greipel marked five victories last season but his scoreless run at the Tour saw even himself question if he’d lost his racing instinct, a statement he retracted in Adelaide.
“That was a big disappointment in the Tour, and then you say stupid things, but I will never lose that,” he said.
“It’s nice when you are 35, everybody tells you, you will get slower but I don’t feel that. I really like to race my bike.”
Greipel has the full support of reduced six-man Lotto-Soudal squad at the Tour Down Under and now the momentum to match as the race moves to hillier ground on Wednesday before another flatter stage to Victor Harbor on Thursday.
“We were calculating we are probably the oldest team around here but I think we have a lot of quality and experience … and you saw that today,” he said.
“We have the right riders still in our team.”
The 2018 Tour Down Under takes place from Tuesday, January 16, to Sunday, January 21.