After remaining largely non-responsive for most of the stage, the peloton dug deep and successfully reeled them in with just over 20km remaining, prompting a final group of six to strike out for the finish line.
"It started to come back pretty quickly when we stepped on the gas," Avery said.
Calder Stewart's Jeremy Vennell was thrust into yellow with the powerful team content to share the coveted jersey among their ranks.
"It's a really nice surprise. I wasn't expecting to be in yellow after today ... I was just lucky enough to get in the move at the finish," Vennell said.
"I think we're looking really good, we're staying in touch with the rest of the competition and we'll bide our time right to the finish."
Dunedin's Joe Chapman, riding for Creation Signs-L&M Group Racing, proved unstoppable in all four hillclimbs to secure the Hydralink/Jesco King of the Mountains jersey.
Share the Road's Chris Macic, of Auckland, snatched the Harcourts Sprint Ace from McCauley, while George Bennett, of Nelson, earned the Co-operative Bank under-23 jersey.
Just 25 seconds separates the top 10 riders with Vennell's time of 4hr 30min 35sec giving him a two-second buffer over Subway's Paul Odlin.