Novak Djokovic avenged his Tokyo Olympics defeat to Alexander Zverev over five sets in front of a roaring crowd inside Arthur Ashe Stadium to move to within one victory of a historic US Open title.
Defeat by Zverev in the semi-finals of the Tokyo Games had denied Djokovic the chance to become the first man to complete the Golden Slam of all four major titles and Olympic singles gold, but the main carrot of the calendar Grand Slam and a 21st major remained within reach.
The German had come from a set down in Japan but here the tables were turned, with Djokovic recovering from that position for the fourth match in a row and then quelling a Zverev fightback to win 4-6 6-2 6-4 4-6 6-2 and set up a date with Daniil Medvedev on Sunday.