Andy Murray dug himself out of a huge hole against Marin Cilic to reach the semi-finals of the US Open for the third time.
At a set and 5-1 down, the third seed looked in danger of suffering one of his biggest grand slam disappointments but he turned things around and levelled the match on a tie-break.
That made Murray a big favourite and he reeled off 11 straight games to win 3-6 7-6 (7/4) 6-2 6-0 and set up a last-four clash against either Roger Federer or Tomas Berdych.
The Scot said: "He played very well at the start and I struggled a little bit. When I managed to get the breaks back in the second set I relaxed a little bit. I've been in that position before when you're serving for a two-set lead and someone comes back and it's tough. The fourth set I played better."
Murray had been due to play on Arthur Ashe but the match was moved to Louis Armstrong because rain had put things behind schedule.
This was the scene of Murray's third-round struggle against Feliciano Lopez, and the early signs were not good as the third seed won only one of the first 10 points, losing his serve to love.
Murray had beaten Cilic in six of their seven previous meetings, including in straight sets in the fourth round of Wimbledon. But the Croatian's only win came here three years ago in the fourth round, although Murray was hampered by a wrist injury.
The Scot had put in one of his best performances of the season to beat Milos Raonic in the previous round and he needed to rediscover that form quickly.
In truth, neither man was playing well, but Murray was just the more reliable.
There was almost a slight twist when Cilic had three chances to retrieve one of the breaks but Murray saved all of them and clinched victory after exactly three hours.