He scored a brace of goals and was man of the match, but this was too late for ex-manager Craig Brown who was sacked on Sunday.
Billy Davies the caretaker manager took control and saw his side 2-0 up at half-time.
Chris Sedgwick had a shot which went for a throw-in and Paulo Vernazza shot wide from 20 yards.
In the 15th minute, Brian O'Neil found Marlon Broomes and Eddie Lewis hit a left-wing cross which Richard Cresswell headed on.
Etuhu was left with a close-range header at the far post which went into the bottom left corner to make it 1-0.
Lewis shot straight at the keeper from close range and Will Hoskins did the same for Rotherham, before Lewis had a shot blocked by the keeper for a corner.
Andy Lonergan made a great save from a Richie Barker header which was going into the top left corner.
Just before half-time a diving header by Creswell was saved well by Mike Pollitt from a Lewis cross.
In the 45th minute Broomes passed the ball to Etuhu who turned and hit a right-foot shot into the top left corner to make it 2-0.
In the 55th minute, Robbie Stockdale fouled Lewis and received a yellow card from Mr Evans.
Rotherham made a double substitution in the 62nd minute bringing on Michael Proctor and John Mullin for Hoskins and Sedgwick.
Substitute Proctor had a shot over the bar and Etuhu cleared from a chance for Mullin.
Broomes had a shot wide of the left-hand post and Barker was booked for a foul on Broomes after 75 minutes.
Cresswell then saw an overhead kick go wide of the right-hand post, before David Healy shot straight at Pollitt.
Preston made a double substitution late on, bringing on Simon Lynch and Andy Smith for Healy and Cresswell and Lynch had the ball in the net but it was ruled out for offside.