Jannik Sinner battles back to set up blockbuster Italian Open final against Alcaraz

World No 1 Sinner sent shock waves through the tennis world with his sensational demolition of Casper Ruud in the quarterfinals, but he was brought back down to earth with a bump after losing the first set of his semi-final against Tommy Paul 6-1.

He battled back to seal a 1-6, 6-0, 6-3 win, but this was a more erratic performance than he turned in against Ruud and that has to give Alcaraz some confidence as he looks to win the Rome title for the first time.

Paul's powerful ground shots rocked Sinner onto the back foot in a stunning opening set and Alcaraz will surely see the success the American enjoyed using that tactic and try to replicate it.

Alcaraz may be able to sustain a groundshot attack on Sinner for longer than Paul could manage, with Sinner telling the Tennis Channel he is unsure whether he is ready to take on Alcaraz in his first tournament back since his three-month doping suspension.

"It's a good question," he said when asked if he can beat Alcaraz. "I think this question is going to be answered in less than two days.

"There have been moments in this tournament where I played great, great, great tennis, like yesterday [against Ruud]. Obviously, he has played more matches than me this year, but let's see what happens.

"Sunday is going to be a great day for me in any case. To come back and make the final in Rome, in such a special place for me, it's incredible. I'm very happy to be here. Let's see what's coming."

Sinner appeared to be struggling with a leg problem in the third set against Paul, with observers at courtside suggesting it looked like a hamstring problem, but Sinner played down the significance of the problem.

"Since the third round, I have a small blister under my feet that doesn't allow me to move in some moments," stated Sinner, who then went on to admit he also has a 'leg problem' that appeared to be a hamstring strain.

"I felt it more today than in other matches. Leg-wise, I'm not concerned. It is just a bit tight, but this is normal.

"There are no excuses and for Sunday, I am 100 percent not concerned.

"I know I'm going to have to raise my level to play against Carlos. We know each other so well and it will be a great match."

Alcaraz also had injury concerns heading into this tournament after he pulled out of the Madrid Masters with a leg problem, but the Spaniard insisted he felt in good shape ahead of his eleventh meeting with Sinner.

"It was a tough match today, he has come through qualifying playing good tennis, so I knew it would be tough," Alcaraz said after he beat Italy's Lorenzo Musetti.

READ MORE: Jannik Sinner demolishes Italian Open favourite Casper Ruud