Jannik Sinner sparks more dating rumours with stunning model who split with F1 star just months ago - as eagle-eyed fans spot 'VERY telling sign' on tennis player's phone at US Open

Defending champion Jannik Sinner booked his place in the US Open fourth round on Saturday – but it was his choice of phone lock screen that stole the headlines.

The world No 1 — who came from a set down to beat Denis Shapovalov 5-7, 6-4, 6-3, 6-3 — was filmed unlocking his phone in the aftermath of his victory.

A zoomed-in photo quickly circulated online, and fans were convinced it showed a picture of Danish model Laila Hasanovic, sparking fresh speculation over the pair's relationship.

Hasanovic, 24, is the ex-girlfriend of former Formula One driver Mick Schumacher, with whom she was thought to have split earlier this year after more than a year together.

The model was present in Sinner's player box at both Wimbledon and Roland Garros, where she was spotted cheering the Italian during his epic French Open final defeat by Carlos Alcaraz in June.

Sinner has been reluctant to discuss his private life, but did admit before the US Open that he was 'in love', adding: 'I don't want to talk about it.'

Defending champion Jannik Sinner booked his place in the US Open fourth round on Saturday

Multiple fans were convinced that the woman in the picture was Danish model Laila Hasanovic

He had earlier dismissed suggestions of a romance when Italian reporters claimed he had been seen on a date in Copenhagen with Hasanovic, insisting: 'No, no, there was no girl.

'I had just some business with a couple of photo shootings there. That's it. Nothing else.'

The 24-year-old's dating history has drawn plenty of attention in recent seasons.

He was previously in a relationship with fellow tennis player Anna Kalinskaya, who herself had dated Nick Kyrgios, and later linked with Russian model Lara Leito, a former partner of Oscar-winning actor Adrien Brody.

But Saturday's 'wallpaper moment' was taken by fans as the clearest sign yet that Sinner has moved on with Hasanovic.

One wrote: 'Him having his gf's pic as wallpaper… and they say he's not a romantic man.'

Another joked: 'Goodbye Jannik Sinner in his single era, you were bigger than the whole sky.'

Hasanovic was seen on the red carpet at the Venice International Film Festival earlier this week

Prior to being romantically linked with Sinner, Hasanovic had dated Mick Shumacher (right)

Some even dragged his rival into the debate, with one post reading: 'Somewhere in New York, Carlos Alcaraz is silently crying into his pillow.'

For now, though, Sinner's attention remains firmly on Flushing Meadows.

He will face Alexander Bublik in the last 16 as he bids to defend the title he won last year.

Ahead of that match one fan declared: 'Sinner is winning on and off the court.'