The Greek came through 4-6, 6-3, 7-6 (10-8) after his 53rd-ranked Argentine opponent missed a match point in the 12th game of the deciding set.

Both men then saved more match points in the tie-breaker before Tsitsipas, a three-time runner-up at the Barcelona tournament, secured a ninth successive win following on from his Monte Carlo Masters title victory at the weekend.

“I was coming close to losing at certain moments in the match. It seemed like a mountain,” Tsitsipas said.

“I reminded myself that I have a headband that I wear here that has a mountain and that I need to climb it, so it kept me going.”

He added, “I feel like having so many matches under my belt and faced situations like this helps for sure.”

The 25-year-old Tsitsipas will face Dusan Lajovic, the world No 59 from Serbia, in the semifinals on Saturday.

Lajovic knocked out 36th-ranked Arthur Fils of France 6-4, 3-6, 6-2 in his quarterfinal.

Casper Ruud, the world No 6 from Norway who was runner-up to Tsitsipas in Monte Carlo, eased past Italian Matteo Arnaldi 6-4, 6-3.

“It is not easy. You are playing for a spot in the semifinals,” said Ruud.

“I was able to come through in the end after a few crazy rallies.”

Argentinian Tomas Etcheverry also booked his place in the semifinals with a hard-fought straight-sets win over the UK’s Cameron Norrie.

Etcheverry, ranked 30 in the world, one place higher than Norrie, edged a tight match 7-6 (7-4), 7-6 (7-1) and will face Ruud for a place in the final.

“I spoke to my coach last night and also my team, that I have to play aggressively to win this match,” the 24-year-old Etcheverry said.

“The tie-break was key. I played really good in that part of the match.”