DeGale was knocked down in the final round of their IBF and WBC super-middleweight title bout but clung on to hear the final bell when scores of 113-113 (twice) and 114-112 in favour of Degale were announced.
The verdict meant DeGale kept hold of his IBF portion of the 12-stone title but failed to add Jack’s WBC belt, for which Smith is the mandatory contender.
With Jack now apparently intent on relinquishing his title to move up to light-heavyweight, Liverpool’s Smith is set to fight for the vacant WBC crown, possibly against the American Andre Dirrell.
Watching at ringside, Smith told iFL.tv: “I’m in a good position because regardless, my next fight is for a world title. Now it’s not going to be in a unification fight, but I get to fight for one of them anyway.”
DeGale had knocked Jack down in the opening round, but his opponent grew into the bout and finished the stronger of the two, flooring the Londoner with a shot that ultimately cost DeGale the victory.
Smith’s promoter Eddie Hearn also admitted plans for a prospective showdown between DeGale and Smith – which could have taken place at Anfield – will now have to be put on hold.
Hearn said: “James DeGale wanted to fight Callum Smith and vice-versa. But it doesn’t matter. All that matters is that he (Smith) is fighting for the WBC title.”
DeGale’s record now stands at 23 wins, one draw and one defeat from his 25 professional contests, and he revealed afterwards that the bout had taken its toll.
The 30-year-old told Sky Sports 1: “He busted my ear drum and I lost my teeth. I thought I’d done enough but it was the knockdown.
“I’ve had 25 fights, I’m going to get better, I want the rematch! I’m glad I’m still the champ and I’m coming home with the title, but I’m so upset that I didn’t come with the WBC belt.
“The main thing is I didn’t lose, I’m still the champ and I can move forward.”
After such an exciting contest another fight against Jack could potentially bring big money, but the WBC champion shrugged off DeGale’s suggestion of an immediate rematch. Jack’s promoter Floyd Mayweather, who expressed anger with the majority draw verdict, also confirmed that his charge will now pursue his career in the heavier category.
Mayweather said: “We don’t need to figure it out. I’m the promoter, this is my fighter. Badou Jack has got too big for 168lbs. We have plans after this fight to move up to light-heavyweight.”
DeGale was fighting in North America for the fourth bout in a row, in the first of which he claimed the vacant IBF title with a unanimous decision win over Andre Dirrell.
He had followed it up with routine points victories over Lucian Bute in Quebec, Canada, and Rogelio “Porky” Medina in Washington DC but seemed on course for his first stoppage in four fights when he knocked down Jack in the last 30 seconds of the opening round.
The 2008 Olympic gold medallist punctuated a cagey start with an overhand left that found Jack’s chin and sent the 33-year-old flat on his back. Jack beat the count but that seemed to give his opponent plenty of confidence.
DeGale was the busier fighter over the next couple of rounds, his superior footwork allowing him to dance in and out, and land some stinging shots in the process. But he showed signs of slowing down in the fourth and fifth, where the most notable action came after the bell when Jack accidentally planted a left hook on referee Arthur Mercante Jr, who was attempting to split the fighters.
Mercante Jr had to be momentarily held up by Jack, and the official admonished himself once he had regained his senses.
That did not distract Jack, who had his best round in the sixth, pinning his foe against the ropes and landing several heavy blows to the body and head.
It was a big right hand that did the damage in the opening minute of the 12th to send DeGale down to the canvas for the first time in his professional career but he got to his feet and finished strongly. It mattered little as the round was a mandatory 10-8 for Jack.