He scored wins over several world champions including Doug DeWitt, Iran Barkley, Thulani Malinga, Mauro Galvano, and Gerald McClellan.
During this time, Benn won the vacant Commonwealth middleweight title with a second-round win over Abdul Umaru, at Alexandra Pavilion on 20 April 1988.
[6] After two more wins, against Sanderline Williams and Jose Quinones, Benn fought WBO middleweight title holder Doug DeWitt of the US in Atlantic City.
[10] Beginning in 1991 with a seventh-round KO victory over Robbie Sims (Marvin Hagler's half-brother), Benn went on a winning streak of six fights leading to another world title challenge.
Galvano was unable to continue in the third due to a severe cut, and—after a controversial dispute at ringside over the official result—Benn was declared the winner by technical decision.
[11] He defended his title against fellow Britons Nicky Piper and Lou Gent, and a rematch victory over Mauro Galvano, before again fighting Chris Eubank—who was now WBO super-middleweight champion—in a unification bout on 9 October 1993.
[12] In February 1995, Benn successfully defended his 168lb title against WBC middleweight champion Gerald McClellan in a highly anticipated bout billed as Sudden Impact.
From Rounds 4 to 6, Benn began to shift the momentum, as McClellan showed signs of distress, repeatedly losing his gumshield, backing off for extended periods, and blinking continuously.
At the time of the stoppage, two judges had McClellan ahead, while the third had the fight even, although these scores did not account for the two knockdowns Benn delivered in the final round.
The injuries left him with significant impairments: he suffers from short-term memory problems, is almost completely blind, partially deaf, and uses a wheelchair.
[15] After his fight with McClellan, Benn had two further successful title defences, with wins against future WBC title-holder Vincenzo Nardiello and American Danny Perez.
[16] He revealed plans for a bout against former WBC super-middleweight world champion Sakio Bika (34-7-3), scheduled for 23 November 2019.
He is an ambassador to the New South Wales Police Citizens Youth Club's (PCYC)[22] and is an advocate for healthy living.
[28] In 2024, Benn joined fellow London boxers – Frank Bruno, Lennox Lewis and Chris Eubank – for a mini documentary, Four Kings.
He survived partly due to the hosepipe he used to recycle exhaust fumes back into his car repeatedly disconnecting.
He considers his suicide attempt as a turning point in his life, becoming Christian shortly after and committing to remaining faithful to his wife.