Tiafoe ends de Minaur's Paris Masters run

After the elation of the biggest win of his career, deflation didn't take long to follow for the ever-willing Alex de Minaur at the Paris Masters.

The Australian battler, buoyed by his breakthrough win over Daniil Medvedev 24 hours earlier, quickly had that sinking feeling again with a straight-sets, last-16 loss to Frances Tiafoe on Thursday.

De Minaur, looking for the victory that would take him back to the Australian No.1 spot and earn him a quarter-final place in a Masters event for the first time, found himself back in the familiar position of being somewhat outgunned, losing 6-3 7-6 (7-5) in an absorbing contest.

Not that he didn't have his chances to make it another red letter day in his career.

The 23-year-old Sydneysider, demonstrating familiar grit to battle back into the contest, had his opportunity to level the match at a set-all when he served for the second stanza at 5-3 up against the US Open semi-finalist at Bercy's Accor Arena.

But the American broke back, took the match into a hard-fought tiebreak and struck decisively in the denouement, firing a backhand service return winner off the Australian's second delivery on his second match point.

It felt like another anti-climactic moment for de Minaur, who played so well in that second set only to be denied the chance of surpassing Nick Kyrgios as his country's No.1 men's player when the new rankings are released next week.

Ultimately, though, the contrast in firepower was evident as the in-form Tiafoe blasted down his 34th winner to go with his 14 aces - compared to the Australian's 18 winners - and wrapped up victory in an hour and 40 minutes.

Still, de Minaur's form over the week should encourage Australian Davis Cup captain Lleyton Hewitt that his leading player is in the shape to challenge anybody with the finals set for Malaga later this month. 

Later in Bercy, world No.1 Carlos Alcaraz, who'll also be Malaga-bound, blasted aside Grigor Dimitrov 6-1 6-3 to book his last-eight place.

Yet French Open finalist Casper Ruud was knocked out by 20-year-old Italian Lorenzo Musetti, who fired 37 winners in his 4-6 6-4 6-4 win and will next have Novak Djokovic in his sights.

Six-times Paris winner Djokovic advanced with a commanding 6-4 6-1 win over Karen Khachanov, cracking 18 winners along the way.

Denmark's ever-improving teenager Holger Rune beat seventh seed Andrey Rublev 6-4 7-5.

Canada's Felix Auger-Aliassime, who like Rublev had booked his place in the ATP Finals on Wednesday, continued his remarkable late-season form, moving closer to a fifth title of the year with a 6-1 6-3 hammering of departing French veteran Gilles Simon.

Fifth seed Stefanos Tsitsipas served strongly to seal a 6-3 7-6 (7-3) win over France's Corentin Moutet and reach the last eight.

The Greek will face American Tommy Paul, who upset No.14 seed Pablo Carreno Busta of Spain 6-4 6-4.