Alex de Minaur has been left the picture of frustration following an epic Barcelona Open semi-final defeat by Spanish wonder kid Carlos Alcaraz after he’d held two match points.

The Australian No.1 was on the verge of by far the biggest win of his clay-court career on Sunday as he twice served for a straight sets win against the 18-year-old on the Rafa Nadal Court.

But when holding a 6-5, 40-15 advantage, de Minaur was beaten by an incredible forehand winner from Alcaraz, who then saved salvaged another match point and went on to level the set.

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After losing a subsequent see-saw tiebreak, de Minaur rallied again strongly in the decider but was eventually decisively broken at 4-5 as Alcaraz went on to celebrate a remarkable 6-7 (4-7) 7-6 (7-4) 6-4 triumph after three hours 39 minutes of exhilarating fare.

“I was lucky … it was an incredible match,” said Alcaraz, while paying tribute to the 23-year-old Sydneysider, who had played the best match of his chequered clay-court career.

The match had been resumed at 2-2 in the opening set on Sunday morning after rain, which had plagued the tournament all week, cut short Saturday’s action.

And for long stretches in the Catalan sunshine, de Minaur had the young home favourite on the run as Alcaraz was hurried into mistakes by the Aussie’s forehand tracers and all-court speed and athleticism.

Alcaraz will play the final later on Sunday against his experienced compatriot Pablo Carreno Busta, who defeated Argentinian sixth seed Diego Schwartzman 6-3 6-4 in the other resumed semi.

But the teenager, who’ll enter the world’s top 10 next week, will have his work cut out as he aims to add to the titles he won at Rio de Janeiro in February and in Miami earlier this month.

For his brutal match lasted two hours longer than Carreno Busta’s, also giving him much less recovery time before the late afternoon final.

Though de Minaur failed to become the first Australian man to reach the Barcelona final since Rod Laver 52 years earlier, he could console himself with the thought that this was the week he proved he really might be able to mix it with the best on the clay.