Rosewood, who had snuck through on the inner before angling to the middle of the track, had established what looked a winning break at the 200m but Johnson never gave up on Dez, who chased bravely to collar Rosewood and score his biggest victory.
"We've had a few problems but we sorted them out and he has definitely hit top form at the right time," Wilson said. "I was happy with him as he had travelled well and was eating up but you just never know on the day.
"Being by Zed, we knew he would handle the conditions and he had a great rider on board. I can't see that well as I'm a little bit colour blind but when he turned in, it looked like he was coming through with a good run and it was a fantastic ride by Chris."
Johnson was his typically relaxed self as he described proceedings about the race he last won in 1991 on Robyn's Affair.
"He travelled nice in the race, although when we moved into second halfway down, he was flat out," Johnson said. "The second horse [Rosewood] kept kicking and he [Dez] just lifted that last bit.
"I wasn't sure if we had got up as I've had a run of seconds and thought I was second again. He's had a few issues in this prep, but I had a look at his run last year, which was huge, and on his last start, it looked like he was back in that form."
The victory made it win No7 for Dez, who spent 2-years on the sidelines with tendon issues after winning two of his first three starts in 2015.
- NZ Racing Desk