Britain's Andy Murray made his earliest Grand Slam exit of the year as Japan's Kei Nishikori fought back to win their US Open quarter-final in five sets.
Murray, seeded second, led by two sets to one but eventually lost 1-6 6-4 4-6 6-1 7-5 in three hours 57 minutes.
The Wimbledon champion lost his rhythm after rain brought the roof across, then his cool when the stadium sound system interrupted a break point.