Tomas Berdych sensationally upset world number one Roger Federer to set up a US Open semi-final against Andy Murray.
It was a performance of sustained brilliance from the sixth seed as he handed Federer his earliest defeat at Flushing Meadows since 2003.
Federer had never lost in 23 night-session matches at the US Open while Berdych had never played one until Wednesday night, but the conditions were certainly to his liking as he powered to a 7-6 (7/1) 6-4 3-6 6-3 victory.
The Czech said: "It couldn't be better. There is no better feeling than to play my first night session against Roger and be able to beat him. There is no better moments than this. I really enjoyed it. The crowd were great and I'm really looking forward to the next one."
Berdych had played very well in his run to the quarter-finals but still went into the match as a big underdog, even though he had beaten Federer in their last grand slam meeting at Wimbledon two years ago.
The top seed began brilliantly, breaking the Berdych serve in the opening game, but the Czech was playing at a high level and, when the Swiss' dropped, he took advantage. The first-set tie-break was a bit of a horror show from Federer but still it seemed there was no real alarm until he dropped serve at the start of the second set.
The 31-year-old then fought back from 0-40 down to hold for 3-2 but, instead of being a turning point, it merely showed how much pressure Berdych was putting on his opponent. The Czech was overpowering Federer and broke again to lead 5-2. The world number one hit straight back but Berdych was faultless on his second attempt to serve out the set.
The Arthur Ashe crowd were stunned when Federer was again broken at the start of the third set, leaving his hopes hanging by a thread. It was far from over, though. Federer had beaten Berdych from two sets down at the Australian Open in 2009 and he retrieved the break in the sixth game when his opponent double-faulted, to huge roars from the crowd.
The noise only increased when Federer made it four straight games with another break, and then five to clinch the set. The world number one certainly had his mojo back and one outrageous backhand in the fifth game of the fourth set left Berdych flat on the ground as he scrambled in vain to reach it.
That took Federer to 0-30 but the Czech hung on, and in the eighth game he had his chance, which he took with a stunning cross-court forehand to leave him serving for the match. He did not falter, powering down four serves to which Federer had no answer and celebrating with clenched fists and a disbelieving smile.