Everyone knew – except, maybe, Novak Djokovic – that change was going to come in New York. But only gamblers, dreamers and the fool on the hill would have guessed the 2020 US Open title would go to a player in his first grand slam final. After nine days of the championships, that player could be Alexander Zverev. In an uneven performance the Russo-German, world-educated fifth seed – in a draw shredded of past champions absent through choice (Rafal Nadal, Roger Federer and Stan Wawrinka), early defeat (Andy Murray) or self‑destruction (Djokovic) – recovered from a poor start to beat the quarter-final debutant Borna Coric 1-6, 7-6 (5), 7-6 (1), 6-3, on Arthur Ashe Stadium. “I just started playing a little bit more aggressive,” he said of how he recovered from a sluggish start. “It was not the level for a quarter-final of a grand slam. I was down 1-6, 2-4, nothing to lose.” For the first time in a decade all four quarter-finalists – Zverev, Coric, Denis Shapovalov and Pablo Carreno Busta – were younger than 30. None has won a grand slam title, the first time that has happened since 2003 at Wimbledon, the year Federer won the first of his 20 majors – at his 17th attempt. Three years ago, Coric beat Zverev here in four sets in the second round. Seven years ago, when they met at the same venue as 16-year-olds in the boys’ championships with no entourage but plenty of dreams, Coric walloped him 6-4, 3-6, 6-0, and went on to win the title. He was the No 1 junior in the world that year, when Djokovic lost in the final against Nadal. In the quarter-finals of this weirdest of grand slam tournaments, they started with a clean sheet. Coric, who had beaten Zverev in three of their four Tour matches, is an excellent player, a fighter with attitude – but not someone who has enough big weapons to consistently stretch the very best on their very best nights. He started like a train but Tuesday was not his night. Coric raced through the first set for the loss of a single game. He should have been two sets up but threw away the second-set tie-break and Zverev came to life. Coric had shown his spirit in the previous round when he came from 2-1 and 5-1 down to save six match points and put the world No 6 Stefanos Tsitsipas out of the tournament. That was a scarily good performance. So was this, although his 2min 15sec absence from the court at 5-5 in the second was inexcusable. Some of these entitled kids need to grow up. Zverev, whose serve is blitz or bilge, hit 135mph at second attempt to force a tie-break in the third set, and reached 137mph on second serve to go 2-1 up. There were two crucial points in the fourth game of the third set. Zverev was adamant he reached a get before second bounce at 0-15 then was powerless to reach a sublime lob that helped to secure the Croatian’s hold for 2-2 – but Coric then blew four break points (one a double-fault gift). Coric served a double-fault. Zverev found a passing forehand from heaven to break and served out the match under serious pressure at the third attempt after 3hr 24min. On Sunday, Flushing Meadows will rise to the first champion born in the 1990s after 63 in a row who were born in the 80s. Who’d have thought it?