David Warner declared before the Ashes series that girlfriend Candice Falzon had "tamed the bull".
Falzon watched on as Warner scored his fourth Test century on Saturday at the Gabba, and detailed how the explosive opener has found an inner-peace after a tumultuous tour of the UK in the winter.
Punished for punching Joe Root in a Birmingham nightclub in July, Warner took his medicine and committed to a strict training regime upon his return to Australia.
Falzon said Warner's 125 from 154 balls on day three of the first Test was just reward.
"When you have that inner peace it makes the job a lot easier," Falzon told AAP.
"Any sports person needs to turn any negative into a positive and he's used it as motivation.
"I'm so happy and so exited for him. I know how hard he's worked the last couple of months.
"It's good to have someone encouraging you along the way but in the end it comes down to yourself.
"I think Dave deserves all the credit. He's the one that decided to make the changes.
Falzon, is the youngest ever professional to compete in the Ironwoman series, and Warner says her training and dietary discipline has been a major influence.
Warner has been put on a strict diet by Australian team doctor Peter Brukner, of low carbs and protein.
The couple train together often and Falzon said Warner has dedicated himself to an active lifestyle.