Rafael Nadal recovers from first-set bagel to beat Dominic Thiem in thriller as US Open conditions get even worse

All junior matches at Flushing Meadows were temporarily suspended as temperatures cleared 37C as Nadal and Thiem struggled through into the early hours of Wednesday morning

The weather at this US Open has been so extreme that it would have been no surprise if lightning had struck for the second night in a row, but in the early hours of Wednesday morning Rafael Nadal narrowly avoided being struck down in the way that Roger Federer had the previous day.

Twenty-four hours after Federer had wilted in the sweltering heat and humidity in Arthur Ashe Stadium and was beaten by John Millman, his great rival survived similarly testing conditions to win a memorable quarter-final against Dominic Thiem.

Nadal won 0-6, 6-4, 7-5, 6-7, 7-6 in one of the longest matches in US Open history. It finished at 2.04am after four hours and 49 minutes of breath-taking tennis. Nadal won the deciding tie-break 7-5 to set up a semi-final meeting with Juan Martin del Potro, who beat John Isner 6-7, 6-3, 7-6, 6-2 in a big-hitting marathon played in even more gruelling conditions in the middle of the day.

Thiem has been the only player to beat Nadal on clay in each of the last two seasons, but this was the 24-year-old Austrian’s finest performance on a hard court. After an electrifying start in which he dropped only seven points in the opening set Thiem matched Nadal blow for blow. However, his failure to serve out for the third set eventually proved crucial.

The match statistics told the story of its quality. Thiem hit 74 winners to Nadal’s 55, but the Spaniard made fewer unforced errors (49 compared with Thiem’s 57) and in the latter stages it was generally the 32-year-old Spaniard who was making the running.

“I just kept going,” Nadal said afterwards. “It was a great battle. The conditions were tough. It was very humid.”

Nadal will be grateful for the chance to rest before Friday’s semi-final. The world No 1 and defending champion has reached the last four after winning three thrilling but draining matches in succession against Karen Khachanov, Nikoloz Basilashvili and now Thiem.

Nadal will face Juan Martin del Potro in the semi-finals of the US Open. (Getty ) (Getty)

Although the players were no doubt grateful not to have to play in the evening, ice towels were still the order of the day. Sweat poured off both men, though at no stage did either wilt physically.

Thiem took the opening set in just 24 minutes. The Austrian found top gear immediately, but Nadal barely got out of first. Remarkably, the Spaniard won just seven points in the first set. It was only the fourth time in his Grand Slam career that he had lost a set 6-0; on each of the previous occasions he had also lost the match.

Nadal quickly rediscovered his form in the second set, but by the time Thiem served at 3-4 the world No 9 had still dropped only four points in his first six service games. It was at that moment, however, that he faltered for the first time and was broken to 15 after some careless errors. Although he broke back immediately he dropped serve again in the next game as two successive forehand errors handed Nadal the second set.

Thiem struggled to cope with the conditions as the heat ramped up in New York. (Getty ) (Getty)

Thiem broke at 3-3 in the third set, but from 5-3 up the Austrian lost four games in a row. Thiem saved two set points at 5-6 but handed Nadal a third when he missed an easy volley and the Spaniard converted it with a thumping forehand winner down the line.

Having broken in the third game of the fourth set, Thiem failed to take two more break points two games later. Nadal broke back to level at 4-4 and when Thiem served at 5-6 and 30-30 the Spaniard wasted a glorious opportunity to go to match point when he netted a high forehand volley. Thiem held serve and then dominated the tie-break, which he won 7-4.

In the deciding set Thiem was staring down the barrel when he served at 5-5 and 0-40 but saved three break points with unreturned serves and went on to hold. There was never more than a one-point difference in the tie-break until Thiem missed a smash at 5-6 on Nadal’s first match point.

Nadal too was drenched with sweat during the encounter. (AFP/Getty ) (AFP/Getty)

At the end Nadal came over to Thiem’s side of the net and embraced his opponent. “I felt very sorry for Dominic,” Nadal said. “He’s a close friend on tour. He’s a great guy and a great player. I just wish him all the very best.”

The tournament’s heat rule, which allows the players to take a 10-minute break between the third and fourth sets, was not implemented in the evening session, but it was during the day, when the temperature in Arthur Ashe Stadium topped 37C. At one stage the heat and humidity was so stifling that all junior matches on other courts were suspended.

Both Nadal and Thiem needed ice towels throughout their match. (AP)

Isner and Del Potro played for more than three and a half hours in a heavyweight contest that must have reminded the American of his marathon defeat by Kevin Anderson at the same stage at Wimbledon two months ago.

The 6ft 10in Isner and the 6ft 6in Del Potro struck 26 and 14 aces respectively and traded huge blows from the baseline. Isner, however, forced only three break points and was unable to convert any of them, while Del Potro took three of his 11 opportunities.

Isner changed his T-shirt 11 times as he struggled with the conditions (EPA)

Although Isner took the first set, it was soon clear that he was suffering in the heat. The 10-minute break appeared to do little to revive the world No 11, who never recovered after losing the first three games of the fourth set.

Isner’s shirt was drenched in sweat throughout the match – he changed it 11 times – and there were moments when he bent over between points in clear discomfort. He estimated afterwards that he had lost 10lb during the match.

The American agreed with Federer’s view that the stadium’s roof might be contributing to the seemingly airless conditions. “It’s tough conditions out there, no doubt,” Isner said. “It's very humid. The air is pretty still for whatever reason.”

He added: “I have never seen Roger sweat, ever. If he's sweating a lot and has to change clothes, then you know it's pretty humid out there.”

Del Potro said of the 10-minute break at the end of the third set: “I lay down on the table and I didn't want to come back again because with this heat it's impossible to play tennis.”

Juan Martin del Potro celebrates his quarter-final victory over John Isner (AFP/Getty)

The popular Argentinian is through to the semi-finals for the third time in the last five Grand Slam tournaments, but he has only played in one final, having won the title here nine years ago.

“I’m so happy to reach another semi-final in my favourite tournament that's very special to me,” Del Potro said afterwards. “Of course beating John in this kind of match is like an epic. We both were tired in the end, we both fought until the end. I think I survived with my serve. That was the only difference, I think.”