Even Roger Federer struggles to do miracles back to back. After saving two match points against Gael Monfils in the 1,200th win of his career, he blew two of his own against Dominic Thiem on Friday when victory would have sent him into Saturday’s semi-finals against Novak Djokovic for the 48th time.

As it is, the world No 1 – who watched the second semi-final of the Madrid Masters on TV after the late withdrawal of Marin Cilic with food poisoning – faces Thiem, eighth in the ATP rankings, who was well worth his 3-6, 7-6 (11), 6-4 win.

The winner of that semi-final plays either Stefanos Tsitsipas – who beat his main rival, Alexander Zverev, 7-5, 3-6, 6-2 – or five-time champion Rafael Nadal, who punctured the revival of Stan Wawrinka by 6-1, 6-2, in 68 minutes in the last match of a long and entertaining day.

Roger Federer beats Gaël Monfils in Madrid and claims 1,200th win Read more

When three match points came Thiem’s way after two hours and 10 minutes of an enthralling contest, in front of Manolo Santana on his 81st birthday on his eponymous court, the Austrian could not hide his joy. Even at 37 and returning to the clay after an absence of nearly three years, Federer remains a formidable scalp.

On Saturday and Sunday Thiem will try to complete the rare treble of beating Federer, Nadal and Djokovic in the same clay-court season. “The test today was huge and tomorrow is a different game,” he said. “Novak has won the last three slams and he is at the top of the rankings again. The challenge couldn’t be bigger.”

Federer was disappointed but will approach the French Open in three weeks’ time with renewed confidence. He said: “Gael and Dominic are tough on the clay so it was a good battle. I feel good on the clay right now.” But he said of the Rome Open next week, “I’m not sure if I’m going to go.”

Stepping into the Austrian’s second serve, he gave Thiem neither time nor room to find a convincing rhythm in the first set. All looked well for the man who makes the difficult look ridiculously simple.

However, he made it too hard for himself in the second-set tie-break, saving five set points but not a sixth, as Thiem smashed a winner to extend the struggle into a third frame, where he finished the job with a solid service game to nil.

Facebook Twitter Pinterest Dominic Thiem boosted his French Open title credentials with an impressive display against Federer. Photograph: Anadolu Agency/Getty Images

There was plenty of edge between Tsitsipas and Zverev when they faced off on Arantxa Sanchez, the tournament’s second court, after the German’s recent criticism of the Greek’s game. The loser, who does not lack for attitude, would only say later, “He’s obviously improved a lot.”

In the closing match Nadal pounced on Wawrinka from the start and won going away. He has lifted this trophy five times; only a fool would bet against him making it half a dozen. The Spaniard said later: “It was one of the days that everything worked out and I have done it really well.”

Earlier Simona Halep, who has been coping with a heavy head cold, gave herself a chance of returning to No 1 in the world for the third time after breaking the stubborn resistance of the resurgent world No 18, Belinda Bencic, to win a ragged, engaging semi-final, 6-2, 6-7 (2), 6-0, at her favourite workplace.

Simona Halep halts Ashleigh Barty's winning run to reach Madrid semi-final Read more

Whether or not Kiki Bertens has done her a favour by putting out Sloane Stephens 6-2, 7-5, is tough to call. The seventh seed said later: “I went to sleep really late last night. The body had to recover from that, so I’m happy to get through here today and really happy to be in another final in Madrid.”

So Halep will either head for Rome as a three-time Madrid champion – which would displace Naomi Osaka at the top of the rankings – or not. As she remarked later: “I don’t want to think about it. For me it’s more important to win the title.”

Either way she will be in good shape to defend her French Open title in three weeks’ time, settling in quickly with her new coach and compatriot, Daniel Dobre, after splitting with the Australian Darren Cahill before Christmas.

A fourth ace lifted Bencic’s wilting spirits at the very end but she handed the match and a fourth bagel of the week to Halep with a tired forehand that barely ruffled the net. She did not feel disposed to talk to the media afterwards.

• This article was amended on 11 and 13 May 2019. An earlier version incorrectly gave Manolo Santana’s age as 80, rather than 81, and said that Roger Federer’s match against Gael Monfils led him to his 12,000th career win. It was his 1,200th. In addition, the final result of the Stefanos Tsitsipas v Alexander Zverev match was corrected because an earlier version had it as 7-5, 6-3, 6-2; it was 7-5, 3-6, 6-2.

