Devin Haney spent the past couple of weeks expecting to enter the biggest fight of his career without his father by his side.

Even as he was prepared for that moment, he never wanted to envision his winning the undisputed lightweight championship under that scenario.

A late-hour travel visa approval allowed Bill Haney to board a pre-dawn flight on Friday, landing in Australia in time to take the lead in his son’s corner. The younger Haney took care of the rest in the ring, outclassing Sydney’s George Kambosos Jr. to retain his WBC lightweight belt while winning the lineal/WBA/IBF/WBO titles in front of a partisan crowd of 41,129 at Marvel Stadium in Melbourne, Australia.

“When we started out, we said we wanted to be the best. It would have hurt me to accomplish this without (Bill Haney) here,” Haney admitted after posting a twelve-round, unanimous decision win on the road. “I’m so thankful. Alhamdulillah, Dad, I’m so thankful.”

Bill Haney was previously stuck in Las Vegas, unable to join Devin on an outbound flight to Australia due to his ETA (Electronic Travel Authority) not being approved at the time. A drug conviction from 1993 kept his case under review for more than two weeks before it was ultimately approved on June 2.

Prior to the elder Haney being cleared to fly, the younger Haney (28-0, 15KOs) was prepared to proceed with Yoel Judah serving as head trainer on fight night. Judah is a longtime friend of the family and Bill’s mentor when he first began in the sport. His son Zab Judah, the former two-division and undisputed welterweight champion, is Devin’s godfather, which left the unbeaten 23-year-old in a situation where he was as close to having family in the lead role without it actually being his father.

The unexpected positive turn late in the week was the final piece in place for Haney to close the show on fight night. A masterclass performance was slightly overshadowed by surprisingly close scorecards of 116-112 turned in Hungary’s Zoltan Enyedi and Canada’s Benoit Rousell, while judge Pawel Kardyni (118-110) scored the bout more in line with the take from home viewers.

Regardless, it leaves Haney as the youngest undisputed champion in the four-belt era and the first undisputed lightweight champion of any kind since the late, great Pernell Whitaker fully unified the WBA/WBC/IBF belts in a first-round knockout of Juan Nazario in 1990.

“This is a dream come true,” noted Haney. “I was going through it without my dad being here. This was a big moment for both of us. We both dreamed of it.”

Jake Donovan is a senior writer for BoxingScene.com. Twitter: @JakeNDaBox