Two-time runner-up Daniil Medvedev overcame stubborn resistance from Portugal's Nuno Borges to book a place in the Australian Open quarter-finals on Monday.

The Russian third seed was made to work hard by the courageous world number 69 before getting over the line 6-3, 7-6 (7/4), 5-7, 6-1 after more than three hours on Rod Laver Arena.

He will meet Polish ninth seed Hubert Hurkacz for a place in the last four.

"Before this match I was feeling 100 percent," said Medvedev, a finalist in 2021 and 2022, losing to Novak Djokovic and Rafael Nadal.

"But he made me run third set and that's why I missed a little bit too much, I was pretty dead to be honest. In the fourth set I managed to raise my energy levels."

Before this year's Australian Open, Borges had never won back-to-back Tour-level matches outside of Davis Cup and his lack of pedigree was ultimately exposed.

The key difference was the unforced error count, with Borges making 66 to Medvedev's 34.

But it was nevertheless a sterling effort by the 26-year-old, who was the first Portuguese player ever through to the second week in Melbourne.

Medvedev's baseline power was a standout factor in the first set, with the only break coming in the sixth game as the Russian dominated long rallies.

Borges bravely held his own until 3-3 in the second set before crumbling under the Russian's unrelenting groundstrokes, conceding the break.

But the world number three then lost focus and his fourth double fault of the match at 30-40 in the next game put the set back on level terms.

It went to a tie-break, with Medvedev surviving another double fault to prevail.

The Russian manoeuvred to the cusp of victory at 5-4 in the third set, but Borges refused to go quietly, breaking before reeling off the next two games to keep the match alive.

It was a wake-up call for Medvedev, who was a new man in the fourth set, racing through it in 24 minutes as Borges flagged.