They were riding single file in the inner of two southbound lanes along Riddiford St towards Newtown about 4.30pm when they say the driver cut them off, and then got out of his car.
"Words were exchanged, he stopped his car in front of us, Laura managed to swerve in front of him and he just came and knocked me off my bike," Mr Roca said yesterday.
"He barged into me and knocked me over. I got up and he came towards me and punched me in the face and I went down again."
He said other motorists stopped to help as the man sped off through a red light, and they provided licence-plate details for a complaint laid with the police yesterday.
He said he was lucky to be left with only a cut lip and sore shoulder and back from the attack, which would not deter him and Ms Crawford from exploring cycle trails in the South Island next week.
"The guy was just so angry that I think it was just his personal problems," he said.
"It seems like such an isolated experience - it is not going to put us off touring or riding the trails of New Zealand."
Ms Crawford, 32, said it was lucky the attacker was unable to throw "a very good punch" to cause more serious harm.
"I don't want to diminish it, because it was absolutely awful, but it was a fluke thing - I don't think anyone should take it as a reason not to cycle."
But the attack has left members of cycling groups worried about its effect on New Zealand's tourist reputation.
"It's the last thing we need," said Cycle Action Auckland chairwoman Barbara Cuthbert.
"The moment I heard about it, I just hung my head in shame and put my head in my hands and thought no, it couldn't be."
Cycling Advocates Network project manager Patrick Morgan, who is hosting the couple at his home, said his organisation would follow the progress of police inquiries.
"Unfortunately, this kind of aggression is not rare in New Zealand," he said.