Greg Vanney's side continued its superb run of form in Ohio. TFC have collected 28 of the 36 points on offer in under eight weeks of regular-season action since exiting the MLS is Back Tournament in the summer.
Toronto FC now have six matches to try to clinch the Supporters' Shield and secure a favorable seeding in the MLS Cup playoffs.
The Canadian club was quickly in the ascendency at Nippert Stadium and took the lead in the 29th minute. The influential Alejandro Pozuelo slipped the ball down the edge of the 18-yard box for Richie Laryea, and the right foot of Patrick Mullins cuffed the Canadian international's intelligent cutback through a crowd. It was one of the few times Mullins managed to shake off ex-TFC defender Nick Hagglund in the opening half.
Cincinnati battled to get into the match after the break but offered little hope of adding to their woeful scoring record this term. If either side looked like adding to the scoresheet in Cincinnati, it was the Reds, thanks to the technical wizardry of Pozuelo.
But TFC almost shot themselves in the foot. Omar Gonzalez conceded a penalty in added time before the Video Assistant Referee granted him a reprieve. Laurent Ciman then played a mindless back pass that hit Quentin Westberg's side-netting, and Hagglund headed over from the subsequent corner.
The final whistle signaled a fifth straight win for Vanney's men, but the haphazard end to the match may act as a valuable wake-up call ahead of Toronto's postseason campaign.