Alex de Minaur has enjoyed a good day in his battle to reach the ATP Finals for the first time, but Australia's main man remains adamant he has "no big expectations" of making it to the end-of-season tennis showpiece.

De Minaur, currently one place outside the top-eight who will qualify for Turin, closed the gap when he eased into the quarter-finals of the Vienna Open with a victory over Italian riser Flavio Cobolli, who was forced to retire with an injury.

De Minaur, who is himself still not 100 per cent after the hip injury that marred his season at Wimbledon and beyond, was left encouraged that he was recovering some of his early 2024 form as he was leading Cobolli 7-6 (7-2), 3-1 when the Italian's troublesome right shoulder prompted him to call it a day.

"I think there was definitely a little bit of that (incremental improvement) today," de Minaur said.

"I felt a little bit more comfortable in the way I was playing, the way I was moving. All around, I was at a very good level."

Of his 22-year-old opponent's injury, he added: "Obviously, I don't want to finish the match like that by any means. I'm wishing Flavio a speedy recovery, he's a hell of a player, hell of a talent and I'm sure the while tennis world wants to see him back on court as soon as possible."

The victory helped de Minaur, currently ninth in the 'Race to Turin', to move back to within 265 points of eighth-place Andrey Rublev, who has also reached the quarter-finals of the other ATP event in Basel this week.

De Minaur needs a deep run both in Vienna and in next week's big points-scoring event at the Paris Masters but is adamant that he is more interested in concentrating on himself than looking at the ATP points situation.

"There's still a lot of guys winning their matches too," de Minaur said.

"I'm doing my best to focus on myself, and do the best I can. No big expectations — I don't know how the body is going to pull up, so I'm just taking it day by day and if I can keep on spending time on court, it's a good thing."

Next up for de Minaur is the challenge of Czech teenage star Jakub Mensik, who beat Miomir Kecmanovic 6-3, 7-6 (9-7) to reach his fifth quarter-final of the year at the age of just 19.

De Minaur, who had beaten Cobolli comfortably at the Australian Open in January, was largely in control again with the Italian never looking completely comfortable with his shoulder problem throughout a match in which he sprayed around 31 unforced errors.

The Italian conjured up his best moments when de Minaur was serving for the first set at 5-4 and earned a break back that dragged the stanza into a tiebreak, which the Australian dominated.

Calling for the trainer after that set while increasingly struggling, it seemed only a matter of time before he was broken again by the solid de Minaur, and once that happened in the fourth game, he offered his hand, clearly not wanting to exacerbate the problem with Italy's Davis Cup defence just around the corner.

Match of the day in Vienna featured Czech Tomas Machac coming from a set down to beat third seed Grigor Dimitrov 6-7 (5-7), 6-4, 6-3.

AAP