The 21-year-old Greek striker, recently signed for £6million from Dutch club Heerenveen, found the net twice in the opening 10 minutes as City kept alive their hopes of winning a place in the UEFA Cup.
But it was a typical City display as Stuart Pearce's side didn't make life easy for themselves.
After looking like running up a cricket score in the early stages, City conceded a goal midway through the opening period.
That knocked them out of their stride and they spent the remaining 65 minutes of the match holding onto a precarious one-goal lead.
City were handed their opening goal in the ninth minute following a terrible blunder by visiting player Danny Collins.
The central defender was caught in possession just outside the penalty area by Samaras as he tried to turn on the ball following a clearance from keeper Kelvin Davis.
Samaras raced clear and fired a fiercely-struck shot across the face of goal and past the helpless Davis.
And barely 90 seconds later, City were celebrating a second goal following equally generous defending from the Black Cats.
Trevor Sinclair beat the offside trap on the right and from his cross the unmarked Samaras found the bottom corner with a terrific volley from 14 yards.
It was the Greek striker's third goal in only four starts since his arrival at Eastlands during the January transfer window.
But if City thought the match was over they were mistaken as Sunderland halved the deficit midway through the half.
Julio Arca's free-kick was headed over the face of goal by Gary Breen for Kevin Kyle to stab home from virtually on the goal-line.
It was Kyle's first Premiership goal and Sunderland supporters showed their optimism by chanting that they were going to win 3-2.
The goal knocked City out of their early fluent stride as Sunderland suddenly sensed they were still very much alive having looked dead and buried after only 10 minutes.
Samaras had a great chance to complete his hat-trick early in the second half but shot weakly at Davis who later did well to keep out a fierce drive from Darius Vassell.
And they looked like being costly misses as Sunderland remained in with a shout as they themselves squandered two great opportunities to level the scores.
Nyron Nosworthy cut the ball back from the right and Dean Whitehead shot wide with the goal at his mercy.
Whitehead then had a drive which was going off target but Arca, sliding in, just failed to connect from six yards when he would have scored had he managed to get to the ball.
City had a strong shout for a late penalty rejected by referee Chris Foy after keeper Davis appeared to foul Micah Richards near to the byline.
Kiki Musampa had a great chance to seal victory but Davis produced another splendid save to beat out his pile-driver.
And any hope Sunderland had of snatching a point disappeared with five minutes remaining when captain Breen was sent off for a deliberate handball, his second yellow card of the match.