It is said in boxing that the only opponent a fighter can never expect to beat is Father Time, but Mike Tyson and Roy Jones Jr still fancy their chances.
Tyson, 54, and Jones, 51, are going head to head in an exhibition bout on Saturday.
The clash, scheduled to take place over eight two-minute rounds, will draw plenty of attention as boxing fans around the world check in on two of the sport's greats.
Although former four-weight champion Jones fought as recently as two years ago, ex-heavyweight king Tyson's last professional contest was in 2005, losing to journeyman Kevin McBride before retiring, saying he did not have "the fighting guts or the heart anymore".
'Iron Mike' could not resist the urge to lace up the gloves again, though, and is far from the first notable name to make an unlikely return to the ring...
'Big George' decided to walk away from boxing in 1977 after losing on points to Jimmy Young in San Juan, Puerto Rico. The heavyweight fell ill in his dressing room after the bout and suffered what he said was a near-death experience, leading to him finding God. A born-again Christian, Foreman opted to fight again a decade on from his previous outing.
After coming up short against world champions Evander Holyfield and Tommy Morrison, it was third time lucky for Foreman when he met Michael Moorer in November 1994. The younger man dominated throughout but, having received a grilling, Foreman turned the bout around in the 10th round, forcing a sensational stoppage. He had claimed the IBF and WBA titles and, in the process, become the oldest heavyweight champion in history at 45.
"It's more than a comeback - I'm fighting to redeem myself." After personal issues outside the ring, Ricky Hatton returned to the sport in 2012 with the aim of making Britain "proud" of him again. A hugely popular public figure, 'The Hitman' had been out of action for just over three years since losing in painful fashion - mentally, as much as physically - to Manny Pacquiao.
The target was to challenge again for a world title. However, the Mancunian's planned journey back to the top hit an early road block in the form of Vyacheslav Senchenko. The Ukrainian crashed the party in Manchester, dropping and stopping the hometown favourite. A heartbroken Hatton knew the game was up and went back into retirement.
SUGAR RAY LEONARD
Sugar Ray was no stranger to a comeback. The five-weight world champion retired on several occasions only to be tempted back, including once for a long-awaited bout against Marvin Hagler that Leonard won via a controversial split-decision verdict in 1987.
A defeat to Terry Norris finally appeared to be the end of the line in February 1991, yet the American laced the gloves up again six years later to face Hector 'Macho' Camacho. At 40, a past-his-prime Leonard was no match for the Puerto Rican, losing by TKO in the fifth. He quit in the aftermath and, despite further talk of yet another return, thankfully stayed away.
A snapped anterior cruciate ligament had seemingly cut short Klitschko's fighting days. The Ukrainian was training to take on Hasim Rahman in 2005 at the time of the injury but decided to forget about the ropes and concentrate on votes instead, choosing to begin a career in politics that would eventually lead to him becoming mayor of Kiev in his homeland.
However, his status with the WBC as 'champion emeritus' - meaning he could immediately become mandatory challenger should he fight again - allowed him a way back in. He duly took it in 2008, stepping up to take on - and beat - Samuel Peter to reign again. The swansong spanned 10 fights, all of them wins, before he returned to his other career.
Just like Tyson, Ruddock had gone beyond his half-century when he announced his decision to fight again. "I see people older than I am. They just sit around and fade away. I don't want to fade away," said the 51-year-old heavyweight who had shared a ring with Tyson (twice) and Lennox Lewis during his prime.
'Razor' had not been in action for 14 years yet stayed sharp by fighting three times in 2015, losing the last of them to Dillon Carman as his attempt to become Canadian champion again resulted in a heavy knockout. To put the age gap in context, Carman was just two years old when his opponent had first won the national title, way back in 1988.