over of the innings.
It was the third time all-rounder Watson had snared Carberry's wicket in this series. In nine Test innings he has been out six times between 30 and 43.
Harris removed Root with an outswinger, enticing an edge to Haddin for 24 in the 43rd over.
Root, like Carberry, had established himself in an 82-ball stay but Harris's perseverance won through in a patient bowling performance.
But Watson's well-catalogued injury jinx struck again when he was unable to complete his seventh over late in the middle session and left the ground for treatment for a right groin problem. He returned to the field late in the day to take the catch to dismiss Stokes.
Australian captain Michael Clarke -- with an unassailable 3-0 lead in the five-match series and the Ashes already recovered -- won the toss and sent the troubled tourists in to bat under overcast skies.
England got to first-hour drinks without losing a wicket but lost skipper Alastair Cook three overs later when he nibbled at Peter Siddle and was caught by Clarke at second slip for 27.
In the 19 tosses Clarke has had as Australia skipper it was only the fourth time he has put the opposing team into bat.
England dropped vice-captain Prior and named Bairstow as wicketkeeper, while Monty Panesar was chosen as the specialist spinner following the shock mid-series retirement of Graeme Swann.
In contrast Australia named an unchanged side for the fourth consecutive Test in the series.