'Can't believe it': Tennis world erupts over 'crazy' US Open drama

Alexander Zverev has won through to his first grand slam final after recording his first career win when trailing two sets to love.

The German No.5 seed overcame a listless start to secure a thrilling 3-6 2-6 6-3 6-4 6-3 win over Pablo Carreno Busta in their US Open semi-final on Friday.

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Zverev, with his back against the wall, raised his game just in time to deny the Spanish 20th seed the upset.

The German looked headed for certain defeat after committing 36 errors through the first two sets but used his versatile game to pick himself up and looked like a completely different player the rest of the way.

“I was actually looking at the scoreboard when I was down two sets to love and I was like ‘I can't believe it, I am playing in the semi-final where I am supposed to be the favourite and I am down two sets to love,” Zverev said after the match.

“I knew that I had to come up with better tennis and I knew that I had to be more stable ... but I am through to my first grand slam final and that’s all that matters.”

Others were also gobsmacked that the German had fought back after dropping the first two sets, describing his win as “crazy” and “insane”.

“I can’t believe he got out of this one,” one TV commentator said after Zverev secured the win on his second match point.

The 23-year-old Zverev became the youngest grand slam finalist since World No.1 Novak Djokovic, also 23 at the 2010 US Open, and the first German major finalist since Rainer Schuettler at the 2003 Australian Open.

He is also bidding to become the first German grand slam champion since Boris Becker won the 1996 Australian Open.

Carreno Busta capitulates after scintillating start

It is Carreno Busta’s second loss in the US Open semi-finals in four years.

After Zverev levelled the match at two sets apiece, the Spaniard took a medical timeout to have his back tended to and the German, with a sudden swagger in his step, got the break he needed in the first game before cruising home.

Carreno Busta was locked in early as he held at love to open the match, turned aside a break point on his next service game, and broke twice for a 5-1 lead before securing the first set.

Things kept going the Spaniard’s way in the second as he pushed Zverev’s back to the wall with three consecutive breaks for a 5-0 lead during a lopsided set in which the mishitting German made 22 unforced errors.

But Zverev flipped a switch and suddenly looked the more confident of the two as he broke Carreno Busta four times over the next two sets while leaning on his serve to put the pressure on the Spaniard's shoulders.

Zverev will face Dominic Thiem in the final after the second seed beat Daniil Medvedev 6-2, 7-6, 7-6 in the other semi-final.

with agencies