Stefanos Tsitsipas passed a mental and physical test as he recovered from 5-2 down in the final-set tiebreak to squeeze into the semi-finals at the Barcelona Open on Friday.

The Greek fifth seed relied on confidence from his Monte Carlo title five days earlier to get past Argentine Facundo Diaz Acosta 4-6, 6-3, 7-6 (0) in a thriller lasting for two and a half hours.

Tsitsipas saved match points as his 53rd-ranked South American opponent repeatedly threatened, finally going over the line as Diaz Acosta drove a forehand return wide.

Tsitsipas barely won his ninth match in a row and admitted he had a lucky escape into the final four, where he will be playing for the fourth time.

“I came close to thinking I could lose the match,” the winner admitted. “it seemed likeĀ  mountain to climb.

“But I remembered that I have a (adidas) headband with a mountain (logo) on it; that kept me going.

“It was difficult to sustain a top level throughout the match. He left everything out there, he’s a good clay player and has a title (Buenos Aires) for a reason.”

Tsitsipas added: “(I had confidence) after having so many matches where I’ve been faced with situations like today.

“I knew that anything was possible. Clau doesn’t give you anything for free. I had to work every single moment.”

The Greek was broken serving for victory at 5-4 in the third and needed to struggle to finally go through in the roller-coaster decider.

“I got tense on my serve, but once I got a hold of that it went back to where it belonged.”

Tsitsipas played Barcelona finals in 2018, 2021 and last year when he lost to Carlos Alcaraz.