Footage of American tennis star Tommy Paul appearing to snub a handshake with Novak Djokovic has resurfaced ahead of his Australian Open semifinal against the world No 5 on Friday.

Paul, who had never made it past the fourth round of a Grand Slam before this run in Australia, booked his place in the last four by seeing off countryman Ben Shelton in four sets on Tuesday.

Now the 25-year-old is just one match away from an unlikely final appearance, though standing in his way is none other than nine-time champion Djokovic.

The latter sealed his own semifinal place with a dominant straight-sets victory over Andrey Rublev on Wednesday, which also saw him equal Andre Agassi's record of 26 consecutive wins at the tournament.

To surpass that achievement he must get past Paul on Friday, and Djokovic may be determined to win in style after a video of his opponent appearing to purposely ignore him at last year's Laver Cup re-emerged this week.

In the clip, Djokovic first shakes hands with Frances Tiafoe at the net after his singles win over the American before embracing Team Europe captain Bjorn Borg.

He then approaches Team World and enjoys a handshake with opposition captain John McEnroe, but as soon as it becomes clear he is heading over to the rest of the team Paul can be seen turning away in an apparent attempt to snub him.

With the North Carolina man facing the opposite direction, Djokovic acknowledges vice-captain Patrick McEnroe and fellow players Taylor Fritz and Felix Auger-Aliassime before walking off.

And as he does so, Paul appears to glance back in his direction after ignoring a potential handshake.

Fans believe Djokovic will now be hellbent on winning emphatically in Friday's semifinal, with one writing on Twitter: 'If Novak remembers, then I can see what's going to happen in semis'.

Another posted: 'I can smell straight sets for Nole'.

A third commented: 'Tommy Paul... poor guy. I doubt Nole will let him win a single game.'

While another simply concluded: 'Maybe just distracted, but Novak will cook him for it'.

After beating Shelton in the quarterfinals on Tuesday, Paul admitted he was thrilled by the prospect of a potential battle with Djokovic in the last four.

'I'm really excited,' he said. 'It wasn't the prettiest match ever today but it was how I needed to play the match. He's a great server. I had to just put in as many returns as I could.

'But I'm really excited, man. It's really cool. I think it's even cooler if I do play (Djokovic). I probably have a better chance of winning if it's Rublev, but to play Novak here in Australia would be awesome.'