Chris Eubank Jr. earned a career-defining victory with a hard-fought unanimous decision over British rival and former two-time world champion James DeGale in a super middleweight grudge match Saturday on SHOWTIME from The O2 in London.

Eubank, the son of British boxing legend and former two-division world champion Chris Eubank Sr., floored DeGale twice en route to the clear decision, which was scored 114-112, 115-112, 117-109.

Working in his first bout with a full-time trainer, Eubank fought a controlled fight. The former world title challenger floored DeGale in a rough moment in the second, stunning his rival with a big left hook against the ropes and flooring him moments later with a strong right cross that sent DeGale to the canvas for just the second fight of his career.

DeGale, who established his championship career as a slick southpaw, was unable to jab at range and couldn’t handle the constant pressure from Eubank. The former Olympic Gold Medalist resorted to lunging from the outside and was largely ineffective on the inside, often clinching while in close quarters.

The second knockdown came in the 10th as Eubank landed a powerful left hook that buckled DeGale with just 30 seconds left in the round. Once again, DeGale tried to clinch to avoid the knockdown, but his hand touched the canvas and was ruled just the third knockdown of his career.

After the fight, DeGale, who was the first British fighter to earn an Olympic Gold Medal and a world championship, appeared to be leaning toward retirement.

Video: Chris Eubank Jr. Reacts To Decision Win Over DeGale

Degale Vs Eubank

Video: Chris Eubank Jr. Reacts To Decision Win Over DeGale