The unbeaten 28-year-old floored Romanian challenger Jo Jo Dan four times in a four-round stoppage win at the sold-out Motorpoint Arena in his native Sheffield, just six months after being stabbed with a machete in Tenerife.
Victory paves the way for a more lucrative fight this summer, with Brook targeting the likes of Juan Manuel Marquez, Marcos Maidana and, of course, fellow Briton Amir Khan.
Brook was always expected to retain his belt, despite Dan being a respectable opponent largely due to his inflated number-one ranking with the IBF.
The Yorkshireman grabbed his world title chance with both hands last year, stepping up in class to grab the IBF belt from American favourite Shawn Porter in August.
However, Brook’s world turned upside down weeks later when he was stabbed while on holiday in the Canary Islands. The ‘Special One’ – with a new record of 34-0, (23KOs) – acknowledges how lucky he is to still be alive, let alone still boxing, and insists he has fully recovered from his injuries.
And so it seemed against Canada-based southpaw Dan, who entered the ring a heavy underdog with a record of 34-3 with 18 early wins.
Brook landed three early right hands which were more sharp than damaging. As the round progressed they had more intent, though, with one in particular catching Dan cleanly in the final minute of the opener.
Brook’s range-finding left set up a hurtful right and then Dan was put down by a sharp uppercut. The visitor got to his feet but Brook took his time and had his man down again with another straightforward, clean right hand.
Dan got up a second time as Brook went looking for the stoppage. The challenger looked to have nothing left, however, and it was early in the round.
Another right cross landed and even a jab had Dan’s legs wobbling. Brook showed maturity to be patient, with 10,000 baying fans on their feet.
Dan somehow saw the bell to end the round and was desperate to regroup in the intervening 60 seconds. He showed his heart, too, coming out fighting in the third despite looking out of his depth against the hometown favourite.
Brook began swinging wildly looking to hurt his man again. Eventually one landed, but again Dan swallowed it and saw the round out.
Dan came out fighting in the fourth and was actually landing occasionally, although Brook remained in charge. He was down again as the seconds ran out in the fourth, a combination culminating in a right putting him to the canvas.
As the bell rang for the end of the round, he was down again – but again beat the count – before his corner decided enough was enough and asked referee Earl Brown to halt the bout.
On the undercard, Doncaster’s Gavin McDonnell won the vacant European super-bantamweight title with a stylish, competitive unanimous decision win against decent Ukrainian Oleksandr Yegorov.
Former amateur star Frankie Gavin eased to victory over Bogdan Mitic on his debut for promoter Matchroom.