Errol Spence Jr.’s highly anticipated return to boxing lasted just one fight. The future Hall of Famer lost to Tim Tszyu by unanimous decision Saturday in Sydney and then announced he will retire from the sport for a second time.

Tszyu, a former WBO junior middleweight titlist, overpowered Spence for the bulk of their 12-round middleweight contest at Afterpay Arena, in what was the 36-year-old American’s first appearance in the ring since his memorable loss to Terence Crawford three years ago.

After the judges’ scorecards were revealed (118-110, 117-111, 117-111), Spence all but confirmed his loss Saturday would be his last fight.

“I think yeah, for sure,” Spence said when asked by Main Event’s Ben Damon if this was “the end of the road” for his career. “I’ve got my faculties intact. My money is good at working for itself. Everything’s good, man. I’ve got a beautiful family, and I thank God I’m gracious to leave this sport with my faculties intact and my family still by my side.”

Spence’s layoff from the sport was evident throughout Saturday’s bout. Though the former unified welterweight champion successfully targeted Tszyu’s body, Spence struggled to apply prolonged pressure and appeared uncharacteristically fatigued as the fight entered the latter stages.

Tszyu, by contrast, grew in confidence and power as the rounds progressed. He was on the attack throughout and consistently looked to attack Spence’s chin. Each time Tszyu connected with a right hand to Spence’s jaw, the crowd cheered.

“I had sleepless nights thinking about, ‘What am I going to feel like facing a legend like that?’ But it was one hell of a show, and I understand why he’s one of the greats,” Tszyu said. “I’d love to fight for a title. That’s what I’m aiming for. But I’ve got to say beating a great like Errol Spence tops a world title.”

Tszyu picked up his third consecutive win, and he continues to rebuild his career after tough losses to Sebastian Fundora (twice) and Bakhram Murtazaliev.

The entertaining main event salvaged a much-hyped Sydney card, which lost two of its undercard bouts due to cancellations.

Americans Jermall Charlo and Stephen Fulton Jr. were contracted to appear in separate fights on the undercard, but both bouts ultimately fell through.

Charlo, who was slated to face Koen Mazoudier, was denied an Australian visa earlier this month. Fulton, who was scheduled to fight Liam Wilson in a world-title eliminator, failed to make weight.

Earlier in the day, Australia’s Paulo Aokuso scored a highlight-reel 10th-round knockout against Luis Antonio Tejeda of the Dominican Republic to capture the vacant IBF Pan Pacific light heavyweight title.

Rising Australian Callum Peters continued his ascension up the middleweight ranks with a seventh-round stoppage of Argentina’s Ivan Ricardo Actis, and Ahmad Reda crushed Paul Fleming in the all-Australian lightweight bout that was ultimately promoted to co-main status.