Adonis Stevenson says he'll be going for a knockout when he defends his World Boxing Council light heavyweight title against Andrzej Fonfara later tonight.

After all, as the late, great trainer Emanuel Steward told him: "Knockouts sell."

"When I get in the ring I'm going for a knockout," Stevenson said. "It's not an option for me to go 12 rounds... if it goes 12 rounds he's going to get punishment the whole time. But I definitely am going for the knockout."

The fight at Montreal's Bell Centre will be a rematch of their action-packed meeting in 2014, when Fonfara sent Stevenson to the canvas but was knocked down twice himself as Stevenson won by scores of 115-110, 115-110 and 116-109.

That decision marks one of just two times in the last 10 years that Stevenson has gone the distance. He beat Sakio Bika by unanimous decision in April of 2015.

The 39-year-old champion, who boasts a record of 28-1 with 23 knockouts, stopped Thomas Williams in the fourth round in his most recent title defense, on July 29 of last year.

Fonfara, 29, brings a record of 29-4 with 17 knockouts to the bout.

Now living in Chicago, the Polish-born challenger says his move to respected trainer Virgil Hunter is paying dividends.

"I'm a much smarter fighter now," Fonfara said. "Mentally, I'm much stronger and smarter. I bettered myself. Virgil has taught me a lot of new stuff... Now I'm ready to show everything in this fight."

While Fonfara is seeking a first world title, Stevenson is already thinking about unifying the division, saying he wants the winner of the upcoming bout between Sergey Kovalev and Andre Ward.

"I want to unify the titles," he said. "I think all the fans want that.

"I'm focused to win this fight with Fonfara and then unify the title. I started (my pro career) at 29 years old. I did not have a lot of amateur fights. My body is still good compared to other fighters that are younger."