Rafael Nadal wins in straight sets 6-3 6-4 6-2 to reach semi-finals
Second seed plays Stefanos Tsitsipas next, who beat Roberto Bautista Agut in four sets
Petra Kvitova beat home favourite Ashleigh Barty 6-1 6-4 - plays Danielle Collins next
Simon Briggs
Daily Telegraph tennis correspondent on BBC Radio 5 live sports extra
Rafa's defining everything with his shape and Tiafoe has no idea what is going on. He's basically having to take orders from Nadal.
*Tiafoe 2-5 Nadal
Frances Tiafoe things he's beaten Rafa Nadal with a dinky drop shot, and Nadal promptly hammers a huge forehand through the American's defences for 30-0.
A backpedalling Nadal pushes a forehand long for 40-15, but he holds as a rushed Tiafoe spoons a backhand out.
Nadal is a game away from taking the first set.
Tiafoe 2-4 Nadal*
Frances Tiafoe rattles through another love hold, tidying the hold off as Nadal overworks a forehand.
Simon Briggs
Daily Telegraph tennis correspondent on BBC Radio 5 live sports extra
Tiafoe's tactical confusion is evident at the moment.
Image source, AFP*Tiafoe 1-4 Nadal
The first long rally of the match and it's Nadal who prevails, Tiafoe scooping his forehand down the line and out, and Nadal passes him nicely for 30-15.
A lovely backhand volley tidies up the hold. 4-1 after 14 minutes. No messing around by Rafa.
Simon Briggs
Daily Telegraph tennis correspondent on BBC Radio 5 live sports extra
Rafa plays the game as much for enjoyment as titles. At this stage, you have to think he'll play until at least the Tokyo Olympics. That should play to his strengths: best of three sets on hard surfaces. If he did do that, however, he may skip the French next year, meaning this year's Roland Garros could be his last.
Tiafoe 1-3 Nadal*
Amazingly, in a match in which Rafael Nadal is playing, it's the crowd who are being told off for taking too long.
This is better from Tiafoe, mixing up his serves and keeping the points short. He holds to love with a long Nadal backhand.
Simon Briggs
Daily Telegraph tennis correspondent on BBC Radio 5 live sports extra
Rafa is spreading the court in such familiar style. He's alternating from forehand to backhand, forcing Tiafoe to do shuttle runs to each corner. As if he's got Tiafoe on a rope.
Image source, EPA*Tiafoe 0-3 Nadal
Terrific hitting from Nadal, working all the angles of the court, and he gets to 30-0 as a stretched Tiafoe nets.
Wallop. Ace number three, and Nadal makes it eight points in a row on serve.
Gigi Salmon
Radio 5 live sports extra tennis commentator at Melbourne Park
The great and good of the tennis world are here today because, before the Kvitova/Barty match, we had a presentation to the latest inductees of tennis' Hall of Fame: France's Mary Pierce and China's Li Na.
Image source, EPATiafoe 0-2 Nadal*
Off forehand from Nadal - oh, and Tiafoe works his return into the net!
The first break goes Nadal's way.
*Tiafoe 0-1 Nadal
Frances Tiafoe steps in to the court, and overworks a big backhand.
Break point, Nadal.
Simon Briggs
Daily Telegraph tennis correspondent on BBC Radio 5 live sports extra
You can see Tiafoe is using his forehand a lot, that's his weapon.
*Tiafoe 0-1 Nadal
Frances Tiafoe gets her own service game going with an ace, but he concedes a point with a wayward whip down the line.
Every time Tiafoe gets his nose in front he just lets fly with a little error that costs him, and another miss on the backhand takes us to deuce.
*Tiafoe 0-1 Nadal
Alrighty then.
That'll be a love hold for Rafael Nadal, courtesy of two aces.
Image source, EPATiafoe 0-0 Nadal*
Rafael Nadal will serve first.
Ready?
Play.
Tiafoe v Nadal
Tiafoe said he had bought his mother a house in Maryland and had helped out his father to thank them for their role in his career.
"The beginning of my career I was trying to do everything for my family," Tiafoe said.
"Obviously now I put them in a great place. Now I'm trying to do it for me."
His opponent Nadal has yet to drop a set in the tournament and thrashed Czech Tomas Berdych to reach the last eight.
"Tiafoe has everything. He's quick. He serves well," said Nadal.
"He's a very dynamic player, aggressive one. Of course, he's dangerous."
Tiafoe v Nadal
Frances Tiafoe came into this tournament with no form whatsoever, having been beaten in the first round in Sydney after losing all three of his singles matches in the Hopman Cup.
In the exhibition event in Perth, Tiafoe fell to Roger Federer, Stefanos Tsitsipas and Britain's Cameron Norrie.
He's now into his first Slam quarter-final, beating Kevin Anderson and Grigor Dimitrov along the way.
Image source, Getty Images
Image source, Getty ImagesFrances Tiafoe is aiming to become the first American man to reach the Australian Open semi-finals since Andy Roddick in 2009.
Roddick got to the semi-finals on four occasions in Melbourne but never made it to the final.
Up next, Frances Tiafoe v Rafael Nadal.