The rookie running back rushed for 38 yards on eight carries, scoring on a seven-yard TD run in the first quarter. He later added a 27-yard reception for another score that put the Bengals ahead for good at 17-10.
Andy Dalton completed 25-of-45 passes for 280 yards with the one TD toss for Cincinnati (1-1), which notched its first win after falling to Chicago in last week's season opener.
The Bengals' defense limited the Steelers to 278 total yards and forced a pair of turnovers in the victory -- only their second home win over Pittsburgh in 12 years.
Ben Roethlisberger threw for 251 yards on 20-of-37 efficiency with a touchdown and an interception as Steelers (0-2) dropped a second straight to start a season for the first time since 2002.