The Kiwis still lead by seven minutes and 54 seconds but anything could happen on the final, 86km stage back into Queenstown.
The stage took its toll on Chapman, home after a full season of road racing for Team Tibco-Silicon Valley Bank.
"Look, that was such a hard stage," she said. "No matter who you were, no matter how fit or talented you were, that was going to hurt... I had to talk to myself to stay in the zone really."
Her riding buddy backed her up in this assessment.
"I just keep lying to myself," Mattocks said. "Saying the top will just be another two corners or so."
"I didn't think there could be more mountains," Chapman quipped over her. "What is this?"
"Perpetual denial for me," Mattocks quipped back. "This is NOT Sydney."
Meanwhile in the open men's, Kiwis Michael Vink and Tim Rush (ONYA Bike) comfortably lead Spot Africa/Insect Science team of Alan Gordon and Timothy Hammond by a massive 1:06:29.
“I think we have found our rhythm this week and just settled into it,” said Vink. “Today was probably one of the more consistent days we have had, we were in the bunch more than usual and we just rode a steady pace up the climb, not trying to drop anyone and felt better for it.
“Tomorrow we just keep doing what we have been doing, don’t change anything, we will just do our thing, not take any risks and make sure we have good tyres on and that the chains aren’t worn. We just need to get it done and enjoy it as well.”
But it's all to play for on the final run home in the mixed open category as New World’s Kate Fluker and Mark Williams (Queenstown, New Zealand) saw their lead reduced to just over six minutes by Joejo Joe Skerman and Josie Wilcox on Stage 4.
“It was quite cool at the start of the stage which was quite nice, we cruised with Kate and Willy for the first 20k and then started the Carricktown climb,” said Wilcox. “Carricktown was an epic climb, over an hour of climbing so it was about pace and not going too hard. We gradually got some distance and just increased and knew we had to get to the descent before them, and then managed to hang on.”
For a full race report and results, visit The Pioneer.