Carpenter connected on boots of 38, 42, 24 and 64 yards in the first half to help the Dolphins (4-3) stay close. His fifth and final field goal came with 2:47 to go in the third period and put Miami ahead for good at 15-14.
Miami's Chad Henne went 24-of-37 passing for 217 yards, no touchdowns and one interception. Hartline pulled down five passes for 53 yards to go with Brandon Marshall's five grabs for 64 yards.
Carson Palmer had a tough day for the Bengals (2-5), going 17-of-38 passing for only 156 yards, with two TDs and an interception.
Terrell Owens hauled down a pair of scoring passes, finishing the day with five grabs for 65 yards in the Bengals' loss.