A method and a system for hydrocracking an oil feedstock to produce a light oil stream without build-up of heavy polynuclear aromatic (HPNA) hydrocarbons in the recycle stream. The method may include hydrocracking an oil feedstock, separating the produced effluent into a first, second, and third product stream, and hydrogenating the third product stream in a third reactor over a noble metal hydrogenation catalyst at an operational pressure equal to or less than the second reactor.