Tyson Fury stayed on course for a hotly anticipated rematch with Deontay Wilder after surviving a dramatic upset bid from Otto Wallin on Saturday night in Las Vegas.

The 31-year-old heavyweight from Manchester overcame a flat opening, a gruesome cut and an unheralded but fearless challenger to take command in the second half of the 12-round fight, winning a unanimous decision by scores of 116-112, 117-111 and 118-110. (The Guardian had it 116-112 for Fury.)

The central crisis arose in the third round when Wallin, a largely unknown Swede who went off as a more than 10-1 underdog, connected with a left hand flush on Fury’s right eye that opened up a wide gash and immediately began streaming blood. After the bell the Nevada Athletic Commission confirmed on ringside TV monitors the cut was the result of a punch and not an accidental clash of heads, meaning the 28-year-old Wallin could be declared the winner by technical knockout at any time if the ringside doctor ruled the wound too severe for Fury to continue.

The Gypsy King navigated a series of hairy moments over the next several rounds as the emboldened Wallin targeted the wound, but Fury imposed his will on the fading underdog from the seventh and made it to the final bell in front of 8,249 spectators at T-Mobile Arena.

“It is all heart and determination,” said Fury, who landed 179 of 651 blows (28%) according to Compubox’s punch statistics, compared to 127 of 334 (38%) for Wallin. “If I can keep going I will keep going. He’s a tough guy. I hit him with some chin shots and some body shots, and he kept coming. He [was] undefeated, but tonight I was the man.”

Fury (29-0-1, 20 KOs) was slow out of the gate from the opening bell, perhaps content to get rounds in after a two-round destruction of Tom Schwarz his last time out in June. Wallin managed pockets of success in the first two rounds by cutting the distance and finding ways inside the seven-inch reach advantage of Fury, who briefly switched to a southpaw stance in the second.

By the third Fury started to find his range and tempo, setting up the right hand with feints and scoring consistently with it. But Wallin opened the first and worse of two cuts over Fury’s right eye toward the end of the round, heightening the drama and putting the favorite’s unbeaten record in legitimate peril.

Wallin (20-1 with 1 NC, 13 KOs) attacked his wounded prey over the next two rounds sensing his chance, targeting the cut and landing blows at a far higher rate than any recent Fury opponent. Meanwhile, Fury’s attack was stunted as he fought of the back foot and instinctively pawed at the worsening gash. The Swede enjoyed another strong round in the sixth, during which referee Tony Weeks stopped the action to have the ringside physician closely inspect Fury’s cut before allowing the fight to continue.

“I tried to hit it even more,” Wallin said afterward. “I know it was a punch that did it. I was happy that he was cut, but I wish I could have put more pressure on it.”

Tyson Fury survived a stiff test from Otto Wallin on Saturday night. Photograph: David Becker/Getty Images

In the seventh Fury sprang from the corner with a renewed sense of urgency, throwing and landing more punches and leaning his 6ft 9in, 254.4lb frame on an opponent who was already showing signs of fatigue. He kept the pressure ramped up over the next few rounds, backing up the gassed Wallin with an uppercut at the end of the ninth that left him saved by the bell.

The Swede appeared to be ready to go in the 11th as Fury poured on the punishment with a series of thudding body shots. But just when it seemed Fury would coast to the finish line, Wallin managed to hurt his opponent with a perfectly timed left hand early in the final round that left the bigger man holding on as the cut spewed blood.

“I did everything I could, I tried my best and Tyson is a great champion,” Wallin said. “It tells me that no one can question my heart or question that I am a good fighter.”

Fury, who ended Wladimir Klitschko’s decade-long title reign four years ago only to surrender all the belts during a 31-month layoff where he underwent public bouts with drugs and mental illness, continues to market himself as the “lineal heavyweight champion”, having never lost his titles in the ring. The actual title belts belong to Wilder, who’s owned the WBC’s version of the championship since 2015, and Andy Ruiz Jr, who captured the WBA, WBO and IBF straps with a shocking upset of Anthony Joshua in June.

Fury has reportedly already signed an agreement with Wilder for a rematch of their epic split draw from last year, but the scheduled 22 February date will likely be postponed to allow for his cut to fully heal.

“Deontay Wilder, I want you next, bum! It is all preparation,” Fury said. “I had a long time out of the ring, [but] next is the big boy, the big ‘Bronze Bomber’ on February 22nd.”