Alex de Minaur has roared into the semi-finals of the Barcelona Open by winning two matches in a long, fortuitous and successful day on the Spanish clay.

While Australia’s No.1 was celebrating his best-ever clay-court run on Friday, he would have been the first to admit fortune had blessed him.

With persistent rain forcing the players to tackle two matches in a day, de Minaur got lucky as his last-16 opponent Lloyd Harris had to retire due to injury after just 20 minutes.

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Then de Minaur faced quarter-final adversary Cameron Norrie in the evening, the Briton appearing out on his feet after having subdued Marton Fucsovics in a draining three hour and 25 minute battle.

But the 23-year-old Sydneysider de Minaur, who’s had many a struggle on the red clay, took his unexpected chance gleefully to overcome Norrie 6-3 5-7 6-1 and advance to a last-four date on Saturday with Carlos Alcaraz.

Spanish sensation Alcaraz thrilled the parochial home crowd by beating top seed and last year’s finalist Stefanos Tsitsipas 6-4 5-7 6-2 in the final quarter-final of a long day — improving his head-to-head record over the Greek world No.5 to 3-0.

The 18-year-old Alcaraz on Monday, when the rankings are updated, will become the 20th teenager to break into the ATP top 10 — and the first since Andy Murray in 2007.

Alcaraz will be ninth-youngest player to break into Top 10 and youngest since Rafael Nadal in 2005.

De Minaur was presented effectively with a short training session in his opening match at the Real Club de Tenis Barcelona as it soon became clear world No.40 Harris was struggling with back spasms.

From game point down in the opening game, de Minaur reeling off 12 straight points to take control and with Harris in obvious discomfort the match was over when the Aussie wrapped up the set 6-0 and the South African offered his hand in resignation.

It gave de Minaur a massive advantage before having to face Norrie, who was still battling Fucsovics 7-5 6-7 (9-11) 6-4 in a ferocious marathon.

When they returned a few hours to the Jan Kodes Court, the last thing the weary Norrie would have wanted to see was the ever-energetic de Minaur bounding around on the other side of the net.

Norrie did, however grab the second set from de Minaur to extend the match but it was clear the fresher player had the advantage in the decider to wrap up proceeding in two hours 10 minutes.

In reaching the Barcelona semis, de Minaur has already matched his 2021 clay court win total (4) this season while Alcaraz is aiming for his third trophy of the season, after he won at Rio de Janeiro in February and in Miami this month.

“I’m playing an incredible level. And I think that I’m ready to get the title,” Alcaraz said after his win over Tsitsipas, who won his second straight Monte-Carlo Masters title last week.

Earlier in the day, Tsitsipas swept aside Grigor Dimitrov 6-1 6-4 while Alcaraz won the all-Spanish match against Jaume Munar 6-3 6-3.