Thomas delight at Porte stage win.
Porte had failed to go with Evans (BMC) up Corkscrew Hill during Thursday's third stage as the 2011 Tour de France champion claimed the ochre jersey.
But the 28-year-old Tasmanian, aided by Thomas and Ian Stannard, turned the tables in stage five to launch himself back into contention for the overall title.
"We knew coming into today that Richie had a good chance the way he was climbing the Corkscrew," said Thomas. "We rode for him from the start and we all gave everything for him. It was great to see him pull it off and it definitely makes up for last year when I cracked and lost the jersey here. It's nice to get that first win for the team.
"We always knew he could (win the stage) but we also knew that Gerro and Cadel were going really well. We knew it would be tough.
"But I saw him attack - I was about 50 metres behind and I was already in the red - and I could see him dancing away. I knew he was in good form. It was great to hear he got the win.
"Obviously we had high ambitions coming into this race. We wanted to win the GC and that hasn't quite happened but to still win a stage is a good result with one day to go."
Thomas crossed the line 10th on the stage and now sits ninth overall, while the top four in the standings are separated by just 10 seconds going into the final stage criterium in Adelaide.
Porte told www.teamsky.com: "The guys were absolutely incredible today. It was a little bit of a shame on the Corkscrew stage as I was a little bit out of position and lost some time. But I felt great coming into today. The team had a plan and the boys were incredible.
Ian Stannard and Geraint Thomas were there to the last minute. They dropped me off right on the front at the start of the climb and victory is credit to all those guys."