Daniil Medvedev came back from two sets down in his last match, but that's not looking likely here.

The Russian 11th seed would need a miracle to turn the tide as he falls 4-0 down in the third set.

He just can't find a way past Learner Tien.

Image source, Getty Images

Alexander Zverev, speaking on court after a straight-set win over Francisco Cerundolo in the fourth round:

"I'm very happy with the match. He's a high-quality player who hadn't lost a set in the tournament before this match. I'm really happy with the performance and to be back in the quarter-finals.

"To be in the quarter-finals, you have to be playing well. The last two sets [against Cameron Norrie] and today were a high level and hopefully I can play even better in the next three matches hopefully."

On the changes he has made to his game recently: "I'm playing a bit more serve-and-volley, I'm hitting the drop shot a bit more maybe, trying to hit my forehand a bit harder - trying to do all the things that the two best players in the world [Carlos Alcaraz and Jannik Sinner] are doing and maybe adding that to my game. We'll see how the year goes."

On his fitness: "I'm as healthy as I've been for the past 12 months. I've been really struggling, I had a lot of issues with my body and a lot of injuries that prevented me from playing 100%. I played through them but I was not really feeling great.

"When I'm healthy, I'm happy on the court and everything becomes a bit easier. I don't want to jinx it but hopefully we have three more tough matches and hopefully I can stay that way."

Alexander Bublik saves the first break point (and set point) with an ace and throws away the second with a double fault, which just about sums up how his serve is going.

Alex de Minaur takes the first set.

Alex de Minaur is so impressive on the run. Alexander Bublik is stationed well inside the baseline as he stretches the sixth seed from one corner to the other but his opponent is equal to challenge. Bublik sends a loose forehand long: 15-all.

De Minaur rushes the net after a big serve return and watches as Bublik's backhand reply goes long.

A forehand winner which wrong-foots a running Bublik on the baseline brings up two set points for the Australian.

Wow. Talk about composure.

Learner Tien has won 10 games in a row against the 11th seed and he wraps up that one with a brilliant drop shot to go a double break up.

Daniil Medvedev looks helpless out there.

Still no break points in this opening set as Alex de Minaur holds to 15 again.

Both players have been a bit messy, sharing 17 unforced errors (10 for Bublik, seven for de Minaur).

That was the first set at a Grand Slam that Daniil Medvedev has lost by a 6-0 scoreline. On his 451st set at a major.

And he could be heading for a second bagel as Learner Tien consolidates the break with a comfortable hold.

Alexander Bublik, sticking with his aggressive approach, tries to drop shot Alex de Minaur. However, the Australian is alert to the danger and rushes the net to whip home a cross-court forehand: 30-15.

Bublik replies with an ace and a bruising down the line forehand.

This could all be over for Daniil Medvedev very quickly.

Learner Tien is on a roll and has got the early break in this third set.

A comfortable hold to 15 for Alex de Minaur. That's the third time in four games that he's only dropped one point on serve.

Daniil Medvedev chunters, while Learner Tien is just too fast around the court.

There are a couple rare misses from the youngster but he holds it together to serve out the one-sided set.

This momentum doesn't look like turning...

That's a lovely stroke from Alex de Minaur, reading a wide serve from Alexander Bublik and nestling a flat forehand around the net post into the corner of the court: 0-15.

Bublik completes the hold to 30 with a couple of well-constructed points, dragging de Minaur wide on the forehand side and following it up with a cross-court backhand for 40-30 before crunching a forehand winner on the approach after finally landing a first serve.

His first serve percentage is hovering around 40%.

Learner Tien just can't miss at the moment.

Another Daniil Medvedev service game goes to deuce and yet again the 20-year-old American converts.

Could the three-time Australian Open finalist be on the wrong end of a bagel here?

Three consecutive backhand unforced errors gift Alex de Minaur a 40-15 lead.

He follows it up with a serve into Alexander Bublik's body and comes on the approach for a forehand drive volley. Bublik, reaching for his backhand, finds the net.

Alexander Bublik hasn't quite found his radar with his serve, following up an ace with a double fault: 15-all

His second serves are considerably slower, offering Alex de Minaur a foothold in points, but the 10th seed comes through the game with a hold to 15.

His final serve drags de Minaur wide and the Australian's stretched forehand whistles past the chair umpire's face. The official widens his eyes and puffs out his cheeks.

That's four games in a row for Learner Tien, who's starting to beat up his more established opponent.

Daniil Medvedev has several game points - double-faulting one of them when going big on second serve.

It's scrappy and Tien takes advantage. His opponent's body language is starting to suffer as a result.

The opening point of the third game plays out like exhibition tennis.

Alex de Minaur is forced to turn and chase back after being lobbed at the net. Alexander Bublik later comes on the approach, forcing the Australian into a backhand lob, which flies a foot or two long. This could be fun.

De Minaur secures the hold to 30 with an ace - his second of the match.

Alexander Bublik comes through that test with flying colours, firing down a big serve at advantage which Alex de Minaur struggles to get a racquet on.

If his first serve starts cooking, it could be tricky for de Minaur to find a way through.

Francisco Cerundolo holds to love but it might be too late, as Alexander Zverev will serve for the match after the change of ends.

One more chance to keep his Australian Open campaign alive.