The southpaw had to withstand an onslaught from Eubank in the latter rounds as the challenger tried to snatch a late victory only to lose on a split-points decision.
Saunders controlled the early stages of the fight, using his jab and fast hands to good use as his opponent struggled to assert himself in the bout.
However, Eubank JR looked to change the fight by getting inside and appeared to find success from sixth round onwards as he landed more meaningful blows on the champion.
His corner clearly thought their man was losing the fight by the tenth as they urged Eubank Jr to find a knockout blow and throw more punches.
The challenger caused problems for Saunders as he was swinging his arms with freedom, but the former Olympian was able to take a points victory to the disappointment of Eubank and his corner.