New York - Olympic champion Andy Murray produced an extraordinary turnaround to dig himself out of a deep hole and safely book his place in the semi-finals of the US Open on Wednesday.

The British third seed was in all sorts of trouble after losing the opening set to Croatia's Marin Cilic and falling 5-1 behind in the second with two service breaks.

But he rallied back to win the set in a tiebreak then rolled through the next two, winning the last 11 games, to claim the 3-6, 7-6, 6-2, 6-0 victory.

The Scot, chasing his first grand slam title, now plays either Roger Ferderer or Tomas Berdych in Saturday's semi-finals. - Reuters