In another unlikely early clay-court event exit, Rafael Nadal was ousted in straight sets by Alexander Zverev while Dominic Thiem came from a set down to beat John Isner and as the two familiar foes set up a semi-final clash at the Madrid Open on Friday.

The Austrian recovered against Isner to win 3-6, 6-3, 6-4 while Zverev won 6-4, 6-4 against Nadal.

Nadal has now fallen early in two clay-court Masters tournaments ahead of the Grand Slam in Paris, after going out in the Monte Carlo quarter-finals last month before winning in Barcelona.

Even in Barcelona, however, Nadal needed to save a championship point to beat Stefanos Tsitsipas in the final.

World No 2 Nadal will be bidding for a 14th Roland Garros title and record-setting 21st major in the French capital.

Nadal suffered a third defeat on the trot as Zverev, seeded fifth, held fort in his quarter-final on Friday. This was the German’s first win against Nadal on clay court.

After losing to world No 8 Andrey Rublev in Monaco, Nadal was convincingly beaten by Zverev and the spotlight will be on the 34-year-old now in Rome next week, his last tournament before heading to Paris.

It started well for Nadal when he broke Zverev to love to lead 4-2 in the first set, Zverev serving a double fault to give away the first advantage.

But the world number five immediately hit back and then pulled away, four straight games clinching him the set.

A whipping forehand down the line put Zverev up another break midway through the second and while Nadal resisted more pressure in the seventh game to hold, Zverev served out an impressive victory after an hour and 44 minutes.

Zverev was on the losing side in the final when Thiem clinched his first grand slam title at last year’s US Open, when he beat the German in five sets.

The world No 4 will be one of Nadal’s fiercest challengers at Roland Garros next month.

After twice finishing as runner-up in Madrid, Thiem will be hoping to go one step further this year but he is in the tougher half of the draw.

In the other quarter-finals, the unseeded pair of Alexander Bublik and Casper Ruud will face off to meet either eighth seed Matteo Berrettini or 16th seed Cristian Garin in the semis.

The 36-year-old Isner has never been at his most comfortable on clay but he caught Thiem cold at the Caja Magica by breaking early to claim the opening set.

But Thiem ripped a forehand pass to open up a break opporunity at 3-2 in the second, which he took when Isner hit the net with a volley.

Thiem was reading Isner’s serve better by the time the match went to a decider but it was not until 4-4 that he struck again, when he chased down three Isner volleys to serve for victory.

He closed out, a forehand volley securing victory in just under two hours.

“He’s one of the best servers in history, especially here in the altitude, it bounces high and it’s so difficult to return,” said Thiem afterwards.

“To start with a break down is almost like losing the first set but I stayed focused, kept a good fifghting spirit. Very few points decide that kind of game and that’s how I turned things around in the second set.”

With AFP inputs