Pat Sims intercepted a Manning pass midway through the third quarter, setting up a touchdown pass from Andy Dalton to Jermaine Gresham. The 10-yard strike extended the cincinnati lead to 24-6 with 6:42 left in the third quarter.
Manning threw his second pressure-induced interception of the quarter with 5:41 left, when he was picked by Nate Clements. The Bengals capitalized on the turnover with a touchdown pass from Dalton to Mohamed Sanu that put the home team ahead 31-6.
Dalton also threw touchdown passes to A.J. Green and Andrew Hawkins earlier in the game as the Bengals jumped out to the lead.
Manning is 22 for 32 passing thus far for 158 yards.
Lawrence Tynes has all six points for the Giants on field goals from 23 and 31 yards.
The game is being televised on FOX.