MONTREAL — Faced with an opponent that gave everything he had to offer, David Lemieux used the plan trainer Marc Ramsay set out for him on Saturday night by defeating Cristian Fabian Rios by unanimous decision.

Lemieux, from Montreal, improved his record to 36-3 with 32 knockouts. Two judges scored the fight 100-90 and the third gave it a score of 99-91.

"I'm not 100 per cent satisfied," said Lemieux. "There are things that I wanted to do 10 times better. Some things that shouldn't happen again, some errors at the start of rounds that cost me the knockout.

"But hats off to Rios. He boxed well and merits all my respect. He demonstrated a lot of courage and adapted well."

The former middleweight champion forced Rios (21-8-3, 6 KO) to retreat to the ropes from the start of the fight, especially during the first two rounds. Even when Rios was able to get a couple of good lefts during a counter-attack, Lemieux left the bigger mess.

Rios, 33, forced Lemieux to miss his target on several occasions while also rolling with the punches in front of 5,026 fans at Bell Centre.

The Argentine was also the less active of the two. He had his best moments in the third and ninth rounds when he was able to get a good number of left jabs, especially in the ninth.

Lemieux attacked Rios's body a lot, a strategy that worked well. After saving himself in the fourth and fifth rounds, it felt as though Rios was less incisive in the sixth when Lemieux placed several good combinations.

"We wanted to attack his body a lot and finish with punches to the head," said Ramsay. "We thought that we could slow him down and that's what we did. It took us two extra round to stop him. Twelve rounds would have been perfect."

After a light ninth, Lemieux came back in the 10th and left no doubt about the result of the fight.

Lemieux took the vacant International Boxing Federation title in June 2015 with a 12-round decision over Hassan N'Dam in Montreal. He then lost to top boxer Gennady Golovkin four months later but stopped Glen Tapia 56 seconds into the fourth round in Las Vegas in May.