Jai Opetaia once again made history for Australia. 

A changing of the guard came with Saturday's cruiserweight championship fight, as Australia's Opetaia earned an upset win over defending lineal/IBF king Mairis Brieidis. Judges John Basile (116-112), Steve Weisfeld (116-112) and Katsuhiko Nakamura (115-113) all scored in favor of Opetaia in the ESPN+/Australia Main Event Pay-Per-View headliner Saturday evening at Gold Coast Convention Centre in the Gold Coast suburb of Broadbeach, Australia.

With the win, Opetaia adds a world championship to a national crown in a stellar amateur that included his becoming Australia's youngest-ever Olympian at age 16 in 2012 London.

Opetaia showed poise, not allowing himself to get overwhelmed by the moment of fighting for his first major title. Briedis—Latvia's first and only boxer to win a world title—landed the more telling blows in the opening round, particularly with his right hand that got the attention of his unbeaten challenger. The defending champion was forced to contend with early adversity, as a cut developed over his right eye.

Ever the professional, Briedis quickly adjusted in round two. Several right hands found their way over the top of Opetaia's high guard, forcing the challenger to frequently clinch. Opetaia gained confidence as the round progressed, boxing on his toes and finding a home for his left hand. Briedis managed an uppercut which was discovered to have broken Opetaia's jaw.

Opetaia stood his ground and successfully went punch for punch with the heavier-handed Briedis in round three. Briedis connected with a right hand early in the frame, only for Opetaia to respond with a flush left. Briedis continued to find himself on the defensive, as Opetaia landed a right hook and later with straight left hands. Briedis flurried in the closing seconds, including a right uppercut that found its mark. 

Briedis came out to a more aggressive start in round four, though largely ineffective. The champion missed with a straight right hand as Opetaia continued to box well. Opetaia moved into position to land a left hand, then boxed from the outside to avoid Briedis' jab. The best was saved for the final 30 seconds, as Opetaia crashed home an uppercut that bloodied the nose of Briedis and left him dazed to the point of heading to wrong corner at round's end. 

Blood was pouring from the nose of Briedis from the end of round four throughout the fifth, which saw Opetaia well in control and repeatedly land clean combinations. The 27-year old Australian southpaw was clinical with his right jab and straight left down the middle, with Briedis unable to adjust. 

Opetaia dialed up the pressure in round six, forcing Briedis to wince in pain from a body shot. Briedis enjoyed occasional but singular moments of success with his right hand, though almost always met with left hand counters from the challenger whose confidence grew as did his lead. 

The second half opened with Briedis claiming a much-needed momentum shift. Opetaia showed the first signs of slowing down, displaying a sturdy chin as Briedis dug deep to land right hands but unable to deliver a sustained attack against the fleet-footed challenger. 

Briedis picked up the pace to the best of his ability in round eight. Opetaia boxed and moved to minimize the impact of Briedis' power shots, successfully countering but also urged by his corner to avoid trading punches with the still dangerous champion. 

Opetaia heeded the advice, reestablishing his left hand with a presence in round nine. Briedis continued to come forward in stalker mode but was consistently beaten to the punch. It changed in the final 30 seconds, when Opetaia's head snapped back following a clean right hand by Briedis.

The late surge served as a major wakeup call. Opetaia attempted to assert himself but nearly paid the price as he was rocked by an uppercut. Briedis poured on the attack, walking through an Opetaia left hand to repeatedly hurt the crowd favorite with power shots on the inside. 

Briedis reached down deep in the final two rounds, though at a point where Opetaia also rediscovered his swagger. A right hand by Briedis once again snapped back the head of Opetaia, who'd landed several right hands preceding the change in tide midway through the round. Briedis shook off a straight left to land a long right hand, also catching Opetaia with a right uppercut near the end of the round. 

Opetaia wisely boxed from the outside in his best effort to run out the clock in the twelfth and final round. Briedis closed the gap and emptied his reserves in his best effort to not allow the fight to go to the scorecards. Opetaia was forced to fend off a last ditch surge by Briedis, who left the challenger pinned along the ropes in the final 20 seconds but ultimately ran out of time. 

Opetaia made national headlines in becoming the youngest Australian ever to box in the Olympics, representing his country in 2012 London. His pro career hadn't quite measured up to his amateur accolades, though managing to make his way to the mandatory contender position in the IBF cruiserweight rankings.

He brought it altogether when it mattered the most, pulling off perhaps the biggest win on Australian soil since Jeff Horn's upset win over Manny Pacquiao to claim the WBO welterweight title five years ago to the day of their July 2017 bout. Horn, however, was considered fortunate to have won a decision over the legendary Filipino southpaw.

There was nothing lucky or fortunate about the accurately scored unanimous decision win in favor of Opetaia, who improves—in every sense of the word—to 22-0 (17KOs). 

Briedis' third title reign comes to a bitter close, falling to 28-2 (20KOs). The loss was his first since a heartbreaking twelve-round, majority decision to the great Oleksandr Usyk in their January 2018 World Boxing Super Series cruiserweight tournament semifinal. The win saw the end of Briedis' WBC title reign, with Usyk went on to fully unify the cruiserweight division before moving up to heavyweight one year later where he now reigns as the unified WBA/IBF/WBO/IBO titlist.

The void left behind was filled by Briedis, though it took two separate title reigns to crown a new lineal king.

The talented Latvian claimed the WBO belt in controversial fashion, scoring a third-round knockout of Krzysztof Glowacki in their June 2019 slugfest as part of season two of the WBSS cruiserweight tournament. The bout included a second round that lasted at least 20 seconds too long and with an additional knockdown scored during that time, providing grounds for an appeal by Glowacki. Briedis was able to retain the win and the title but was ordered by the WBO to enter an immediate rematch.

Briedis vacated the belt due to his commitment to the WBSS tournament where he was contractually bound to the final with then-IBF champ Yuniel Dorticos. The bout was delayed several times due to the WBO investigation as well as the pandemic before moving forward in September 2020, with Briedis scoring a twelve-round unanimous decision to enter his third reign. 

Just one successful defense followed for Briedis, stopping overmatched Artur Mann in the third round of their championship fight last October in his Riga hometown. The reins are now handed to Opetaia, the first Australian boxer—and also first of Samoan descent—to claim true lineal championship status in the 43-year history of the cruiserweight division. 

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