A golden opportunity for Jannik Sinner goes begging! Carlos Alcaraz poorly executes his drop shot and Sinner gets there with time to spare. However, his cross-court backhand clips the top of the net.

No matter! Alcaraz sends a backhand wide!

Those groans are replaced by cheers as a big second serve down the T sends Carlos Alcaraz scrambling.

The crowd groans as Jannik Sinner sends a shot wide.

A forehand winner with both feet off the ground followed by a wide serve which ricochets off Carlos Alcaraz's racquet and into the net.

Jannik Sinner has saved another break point in Turin - I make that his 13th.

Tie-break time!

Jannik Sinner fires down a huge second serve to save set point!

We have a break point! And it's also set point for Carlos Alcaraz, who comes out on top of a net battle.

Carlos Alcaraz's forehand, which was a bit iffy in the opening couple of games, is back to its best at the business end of the first set. I think I need a keyboard shortcut for forehand winner down the line...

A whipped cross-court forehand from the Spaniard takes the 12th game to 30-all.

Jannik Sinner shuts down any suggestion of a break point with a well-placed ace but Alcaraz earns deuce with a delicate drop shot.

Carlos Alcaraz gets down low for a forehand volley from outside the service box?! He gets a little stranded as he comes into the net but Jannik Sinner can't execute a tricky lob.

He holds to 15 with a forehand down the line and Sinner once again finds himself serving to stay in the opening set.

Three big first serves. Three brisk points. 40-0 to Jannik Sinner.

The Italian loses his radar a little, including sending down a double fault for 40-30, but recovers with an ace.

Carlos Alcaraz jogs back into position. Jannik Sinner is serving to stay in the set.

While Carlos Alcaraz receives treatment, Jannik Sinner does a few keepy uppies with a tennis ball.

Jannik Sinner sprays a forehand winner to get the crowd on their feet. Carlos Alcaraz says anything you can do, I can do better, sending down a booming forehand of his own to hold to 30.

At the change of ends, the physio comes out to have a look at Alcaraz's right thigh. The Spaniard is taking a medical timeout.

He was stretching his leg at the end of Sinner's previous service game.

That's more like the Jannik Sinner we've seen this week! He finds a couple of big first serves, including a fourth ace of the evening, to race to 40-0.

He blots his copybook with a simple forehand into the net but serves and volleys off a wide serve to close out the hold.

Anyone else sensing a lot of tie-breaks to come?

Laura Robson
Former British number one on Sky Sports

What I loved most about that Sinner backhand line winner was straight afterward you saw the reaction from Alcaraz, but a minute after that when he was at his towel box he gave Sinner's camp a little nod of approval.

So it was a smile shared between the two of them.

Turin erupts as a Jannik Sinner backhand winner kisses the tramline.

However, Carlos Alcaraz responds with a body serve followed by a well-executed serve and volley to hold to 15.

Still no sign of a break point.

After back-to-back deuce games, Jannik Sinner holds to 15.

It's not as comfortable as the scoreline suggests - both players have produced a number of uncharacteristic groundstroke errors - but he seals the hold in style, dragging Carlos Alcaraz across the baseline before sending down a powerful forehand winner.

What was I saying about Jannik Sinner and longer rallies? Don't listen to me. After trading several cross-court forehands, Alcaraz pummels a backhand down the line for advantage.

Sinner then sends a forehand long to secure the hold for Alcaraz.

Jannik Sinner is just starting to get the edge in the lengthier rallies. He clips the baseline a couple of times for 15-all before Carlos Alcaraz fires a forehand long.

The Spaniard retakes the lead for 40-30 but fires a routine forehand into the net.

Jannik Sinner maintains his composure after the delay, coming into the net to bury a volley before firing down an unreturned serve to hold.

Play resumes after an 11-minute delay.

It's deuce in the fourth game.