"At the top of the straight he was the one you wanted to be on but he was going to hit the front too early," Price said.
"It was a long way up the straight. I was looking for the post but he was too strong."
Newitt broke a frustrating run of outs in winning the classic.
"He's just an out-and-out stayer who has got class written all over him and he just gave me the perfect ride today," Newitt said.
The Derby was run at a strong gallop with the outsider Iron Boss taking up the lead role from Shards.
Tarzino was eighth in the running line with Etymology making his bid to the winner's inside while Kia Ora Koutou was shuffled out when the field bunched.
Newitt allowed Tarzino to cruise up to the weakening leaders and he quickly put a two-length margin on the runner-up and held his advantage to the finishing post.