Rublev knocks out Rune in five-set epic

Andrey Rublev confessed to surviving a game of Russian roulette after saving two match points to scrap his way into the Australian Open quarter-finals for a second time.

Rublev staged a stunning fightback in the match tiebreaker to secure a 6-3 3-6 6-3 4-6 7-6 (11-9) victory with a dead net cord winner on his third match point against rising Dane Holger Rune on Monday.

At the end of five gripping sets, ninth-seeded Rune raced to a 5-0 lead in the breaker and was also up 7-3 before suffering a dramatic collapse.

Fifth seed Rublev snatched victory when his backhand return hit the net tape and fell over to send the teenager crashing out of the Open on Rod Laver Arena.

The result, settled in three hours and 37 minutes, set up a blockbuster quarter-final clash with nine-time champion Novak Djokovic.

The superstar Serb made short work of local hope Alex de Minaur 6-2 6-1 6-2.

"It's not a rollercoaster, it's like they put gun to your head," Russian Rublev said.

"Rollercoaster is more easier, man."

Rublev was twice up a set, only to be pegged back, and trailed 5-2 in the final set.

He saved his two match points to send the fifth set to the match tiebreaker and won eight of the last 10 points to seal victory.

"I never was able to win matches like this," Rublev said.

"Especially in very special tournament like Australian Open, to be in quarter-final is something that I will remember for sure all my life.

"I have no words, man. I'm shaking."

Ben Shelton quickly followed Rublev into the quarter-finals with an equally enthralling win over fellow American JJ Wolf.

The 20-year-old world No.89 was a first-round loser in his only previous grand slam appearance, at last year's US Open.

But he is going deep into the second week in Melbourne after prevailing 6-7 (5-7) 6-2 6-7 (4-7) 7-6 (7-4) 6-2.

"It's been a dream so far," Shelton said.

"It was definitely a gruelling match.

"There was a lot of swings throughout the match ... and I really focused on, in the fifth set, just being energetic, trusting my fitness and just hustling, being courageous.

"I did a really good job of competing at the highest level in the fifth set."

Bidding for an improbable semi-final berth in his first Australian Open, Shelton will play unseeded countryman Tommy Paul, who overcame Spanish world No.25 Roberto Bautista-Agut 6-2 4-6 6-2 7-5.