When Gennady Golovkin and Saul 'Canelo' Alvarez meet in Las Vegas on Saturday, they have the opportunity to define both their own reputations and the era in which they fight.
The heavyweight division is viewed as the traditional location of boxing's glamour bouts but Golovkin and Alvarez will add to an esteemed middleweight tradition when the Kazakh superstar puts his WBA, WBC and IBF belts on the line at the T-Mobile Arena.
Here we look at some of the great contest to have taken place at 160lbs through the ages – bouts that GGG v Canelo has every chance of being mentioned in the same breath as, should it live up to lofty expectations.
Tony Zale v Rocky Graziano II (1947)
In the second fight of a bloody and brilliant trilogy for the middleweight title, defending champion Zale tore after New York favourite Graziano, having climbed off the canvas for a stunning comeback knockout win in their initial 1946 encounter. Graziano was badly cut above the left eye, with his right swollen shut from a left hook that forced him to take a knee. But, as Zale tired amid searing heat at Chicago Stadium, a desperate Graziano turned the fight around with a thudding body shot in the fifth and emphatically ended matters in the next session. Zale would have the final word on the rivalry, scoring a three-round TKO 11 months later.
Gene Fullmer v 'Sugar' Ray Robinson II (1957)
Widely regarded as the finest boxer of all time, Robinson won the middleweight title a remarkable five times between 1951 and 1960. Fullmer owns the rare distinction of holding a winning record against Sugar Ray, having triumphed twice and drawn one of their four bouts. However, it is Robinson's victory in their second encounter at Chicago Stadium that lives longest in the memory. Reigning champion Fullmer was narrowly ahead on the judges' scorecards when Robinson landed an exquisite left hook on his chin to end the argument in the fifth. He later called the blow "the most perfect punch of my career".
Nino Benvenuti v Carlos Monzon I (1970)
Monzon ventured out of his native Argentina to face Benvenuti in Rome, with the Italian idol and reigning WBC and WBA middleweight king a heavy betting favourite. The visitor made a mockery of his underdog status, picking apart the skilful but ageing champion before a shuddering right hand brought the end in round 12. A three-round blowout in the rematch was the first of 14 successful title defences for the rangy and relentless Monzon – a spell of dominance that ran until his retirement in 1977.
Marvin Hagler v Thomas Hearns (1985)
A bout never absent from the conversation when the thorny issue of the best fight of all time is discussed, "Hagler/Hearns" has become a descriptive shorthand for whenever tactics are abandoned and all caution, along with every punch in the book, is thrown to the wind. After a tempestuous build-up, Hagler responded to the opening bell by winging a wild right hand narrowly over Hearns' head. The action never let up from there.
Hearns brazenly backed the power that had wrecked Roberto Duran at the same Caesars Palace and rattled Hagler with an early right hook. Plenty more followed and the unified champion was also cut, but Hearns ended a breathless first round staggered by a left hook and follow-up right. The relentless pace ultimately took more out of Hearns and Hagler, fearing defeat after the ringside doctor was invited to inspect his wound, uncorked a brutal right that sent his foe tottering across the ring. It rendered Hearns defenceless for the finishing salvo that ended seven minutes and 52 seconds of utter mayhem.
Marvin Hagler v 'Sugar' Ray Leonard (1987)
Also a conqueror of Duran and Hearns, Leonard was persuaded to end a three-year hiatus and box as a middleweight for the first time in a Las Vegas money-spinner against Hagler. It seemed a fanciful mission for the two-time former welterweight king, whose retirement had been partially enforced due to a detached retina, but Leonard called upon every facet of his quicksilver skillset and pulled through a punishing ninth round to claim split-decision victory. The verdict remains hotly disputed 30 years on, not least by Hagler, who quit the sport and did not return when he was unable to secure the rematch he craved.
Iran Barkley v Roberto Duran (1989)
With Hagler settling into retirement in Italy, Leonard up at super-middleweight and Barkley having shockingly knocked out Hearns to win the WBC title, a golden middleweight era appeared to be at an end. But the last of the 'Four Kings', the 37-year-old Duran, had designs on redemption and prevailed in an Atlantic City barnburner. The veteran repeatedly slipped Barkley's ramrod jab to send home booming rights, although there was work to be done at halfway. A left hook spun Duran around in eight but Barkley's left eye was closing with the Panamanian hero coming on strong. A five-punch combination dumped Barkley in his own corner in the 11th and probably the greatest lightweight ever closed out a split-decision triumph to become a four-division champion.
Bernard Hopkins v Oscar De La Hoya (2004)
Hopkins and De La Hoya will sit ringside on Saturday in their current guise as promoters, having steered Alvarez towards a shot at greatness. Their meeting for the unified middleweight crown 13 years ago throws up some uncomfortable omens for their protege. De La Hoya was boxing's first six-weight world champion but fighting at middleweight for the second time. Hopkins was unbeaten in 11 years and making his 19th title defence. Although both men had their moments in a tactical, technical opening half, Hopkins's status as the seasoned middleweight came to bear fruit as he ground De La Hoya down before leaving him writhing with a withering left to the midsection in round nine. Golovkin's 19th defence, against a Hispanic fighting icon, comes this weekend.
Jermain Taylor v Kelly Pavlik I (2007)
Taylor ended Hopkins' record run in 2005 and held off the veteran in a rematch. Following three underwhelming outings as champion, Pavlik ended any notion of Taylor becoming boxing's next superstar. It looked over in the second, when a right to the temple from Taylor scrambled Pavlik and a crunching follow-up combination sent the Ohio man limply to the canvas. Somehow, he survived the crisis and staggered through to the end of the round. By the next session Pavlik was firing back with solid rights and completed a stunning turnaround in round seven, driving Taylor back into his corner and sapping him with uppercuts and hooks as he slumped on the ringpost.