Sergio Conceicao's men needed a win to guarantee second spot in Group G ahead of RB Leipzig and a place in the first knockout round - where it fell at the hands of Juventus a year ago - and it might light work of a poor Monaco side at Estadio do Dragao.
Aboubakar took advantage of the Ligue 1 champions' pedestrian defending to score twice inside the opening 33 minutes before Felipe and Rachid Ghezzal were sent off after a clash in the centre circle.
Yacine Brahimi extended Porto's lead before half time and when Kamil Glik pulled one back for Leonardo Jardim's beleaguered troops with a penalty just after the hour mark, Porto ruthlessly powered forward to restore their three-goal cushion through Alex Telles.
Second-half substitute Radamel Falcao then scored against his former club but there was to be no Monaco fightback as Tiquinho Soares wrapped up a result that leaves Monaco out of the competition with four defeats and two draws from six games, ending a miserable campaign from last season's semi-finalists.
Porto, meanwhile, will hope for a favourable draw as it aims to go one better than 2016-2017 and reach the quarter-finals.