A far from perfect tournament will feature the perfect semi-final line-up here tonight. After a week in which the US Open has been dogged by criticism of its scheduling of matches and its failure to protect the courts from the rain, the top-four seeds will contest the semi-finals of the year's final Grand Slam event for the first time for 19 years.
Andy Murray and Rafael Nadal will meet for the 17th time in their careers after coming through their quarter-finals in contrasting fashions yesterday, the Scot winning a gruelling four-set battle with John Isner and the Spaniard dismissing Andy Roddick in straight sets. Murray and Nadal will play the second semi-final in Arthur Ashe Stadium – a third match in three days for both men – after Roger Federer and Novak Djokovic, who start at 5pm BST, meet for the 24th time. The final has been moved to Monday, starting at 9pm BST.
The frequency of the meetings between the big four tells you everything about how they are dominating the modern game. They would have each reached the semi-finals of all four Grand Slam tournaments this year if an injured Nadal had not lost to David Ferrer in the quarter-finals in Melbourne and if Federer had not let slip a two-set lead against Jo-Wilfried Tsonga in the last eight at Wimbledon.
In beating Isner 7-5, 6-4, 3-6, 7-6, Murray became only the seventh player in the Open era to reach the semi-finals of all four Grand Slam tournaments in the same season. The others are Nadal, Federer, Djokovic, Rod Laver, Ivan Lendl and Tony Roche.
However, it remains to be seen how much yesterday's match will have taken out of the Scot, particularly after he hurt his back in a fall. "It was sore right at the end," Murray said afterwards. "I just have to see how I feel in the morning, but I feel good just now."
Having initially taken control, Murray was pushed hard by Isner in the latter stages of a match that lasted nearly three and a half hours. The 26-year-old American, playing in his first Grand Slam quarter-final, used his 6ft 9in frame to hit his cannonball serves and went for broke on his returns to play some of the best tennis of his life.
The midweek rain seemed a distant memory as the match started in glorious sunshine and rapidly rising temperatures in Arthur Ashe Stadium, with Michelle Obama among those in the crowd. There was nothing in it for the first 10 games, but at 5-5 two splendid forehand cross-court pass winners and a double fault gave Murray the chance to break, which he did by firing a return into the feet of the onrushing Isner. Murray served out for the first set and took the second after breaking to love in the opening game.
In the third set Isner threw caution to the wind. The world No 22 became more aggressive on his returns and reaped an immediate reward, making his first break in the second game. Murray made a huge effort to break back in the fifth game, forcing break point with a wonderful lob after some superb defence, but Isner held on and served out for the set, despite feeling a problem with his right ankle.
Serving at speeds of up to 140mph, Isner smashed 17 aces to add to the 77 he had hit in the previous four rounds – more than any other player has hit here this year – and Murray found him increasingly hard to break. The Scot himself concentrated on getting more of his first serves into play, but Isner struck some big returns, used his reach to cut out attempted passing shots and hit the ball with impressive power from the baseline.
At 4-4 in the fourth set Isner had two break points, but Murray saved them with an ace and a service winner. The Scot, who had maintained a consistently high level throughout, went within two points of victory when Isner served at 5-6, but the American held firm to force a tie-break.
Thanks in large part to his serve, Isner has a superb record in tie-breaks. He has won more than any other player this year and had won nine in succession going into the match. Murray, however, played the tie-break superbly. Isner served a double fault at 1-1 and Murray quickly took a 4-1 lead with a big forehand and a majestic backhand cross-court winner. At 2-5 down Isner put an attempted drop shot into the net and on match point he failed to find the court with his return.
"I thought it was a really high standard today," Murray said afterwards. "I thought I played really well. I hit the ball very clean from the back of the court. When he's serving you have no option other than to just try and get yourself in the rallies. You're under a lot of pressure on your own service games, so you don't want to just be rash and start trying to make huge winners or do anything stupid. I didn't give him too many opportunities to break me and did a good job on my own serve."
Nadal, who crushed Roddick 6-2, 6-1, 6-3 as the American struggled with a thigh problem, has beaten Murray 12 times, but all four of the Scot's wins have been on hard courts. He will take particular encouragement from his victory in the semi-finals here three years ago, which was one of the best performances of his career. With Nadal improving with each round here, the Scot will almost certainly have to match it if he is to reach his fourth Grand Slam final.