Porte has finished fourth in the race in 2014, before finishing second in 2015 and 2016, and seemed satisfied to have finally won a race that has long eluded him.
“It’s an incredible relief to have won,” Porte said after confirming his victory on stage six in Adelaide.
“I think back to nine years ago when this race really kicked off my career. This is where I came a wild card, then two years later I was in the WorldTour. So to win it is a massive relief.”
Porte was also pleased with the performance of his team, who looked after him well throughout the race.
“Quite a few of the guys here will do a program in the lead up to the Tour de France with me. That’s exciting that I’ve got a team built around me for the first time ever.
“I’ve often been the plan B but BMC Racing Team has put a lot of faith in me this year. I think today I’ve shown that I can repay that faith they’ve put in me.”
Watch: Tour Down Under stage five highlights
Inevitably the performance will be used as an early indication of Porte’s shape as he builds towards the Tour de France in July, and BMC Racing sports director Fabio Baldato was pleased with his man’s early season form.
“I’m really, really proud of Richie Porte and the entire team. We came here wanting to win with Richie and he was really motivated for a good result, and good start to the season. The team was just perfect.
“I think this is a really good sign for Richie for the rest of the season. To start the year here well on home soil gives him a lot of confidence for when he returns to Europe.”
Porte will now spend a few more weeks in Australia, competing at the Great Ocean Road Race on January 29, before starting his European season at Paris-Nice in March.