LeGarrette Blount ran for 127 yards and two scores while Tom Brady completed 19 of 26 passes for 222 yards and two touchdowns as the Patriots pulled away for a 27-16 win on Sunday.
Steelers quarterback Landry Jones played capably while filling in for Roethlisberger, who watched from the sideline after undergoing left knee surgery last week.
Making just his third career start, Jones threw for 281 yards with a touchdown and an interception but undermanned Pittsburgh (4-3) lost its second straight when its defense failed to keep Brady under wraps.
New England (6-1) remained perfect since Brady returned from his four-game "Deflategate" suspension, emphatically responding to a push by the Steelers with a pair of second-half touchdowns. Brady connected with Rob Gronkowski for a 36-yard touchdown in the third quarter then used another 37-yard catch and run by Gronkowski to set up Blount's second touchdown run that put New England up 11 with just under 12 minutes to go.
Brady improved to 9-2 against the Steelers, throwing for 26 touchdowns and three interceptions. Most of those came against far more intimidating versions of a Steelers defense than the one he faced Sunday.
Pittsburgh came in hurting with Roethlisberger and defensive end Cam Heyward both out. The Steelers pushed the Patriots at times behind Jones, running back Le'Veon Bell and wide receiver Antonio Brown. Bell finished with 149 yards of total offense and Brown caught seven passes for 106 yards, but too often Pittsburgh settled for field goals (or field goal attempts) when touchdowns were required.
Mistakes that could hardly be blamed on Jones didn't help. A second-quarter touchdown pass to Darrius Heyward-Bey was called back because of a holding call, one of 10 flags against the Steelers. Pittsburgh fell to 11-10 in games not started by Roethlisberger since 2004.
Blount, facing Pittsburgh for the first time since the Steelers cut him when he walked off the field with the clock still running in November 2014, hurt the Steelers after halftime. He ran for 74 yards following the break, including consecutive runs of 11 and 25 yards that set up Gronkowski's eighth touchdown in five games against the Steelers.
The 39-year-old quarterback who once ran the 40-yard dash at the combine in a not-so fleet 5.28 seconds can still run away from the bad guys. Brady ran for three first downs in the first half, mashing his way on a quarterback sneak and twice escaping pressure and outrunning defenders a decade or more younger for the necessary yardage.
New England kicker Stephen Gostkowski missed a regular season extra point during his rookie year in 2006 and then didn't miss another one until last week against Cincinnati, an NFL record streak of 479 attempts between misfires (though there was that costly missed kick in last year's AFC championship game). Gostkowski didn't have to wait nearly as long until watching a second one go astray. Gostkowski misfired on a third-quarter extra point that kept the Steelers within seven.
Pittsburgh's Chris Boswell had his issues. He sent a 42-yarder in the second quarter wide right and missed a 54-yarder with the Steelers down two scores in the fourth quarter.
Up next, the Patriots visit the Buffalo Bills and the Steelers visit AFC North rival Baltimore Ravens in November.