Jannik Sinner had to change tactics to turn the tables after dropping his first two sets, but successfully reversed course for a 4-6, 4-6, 6-1, 6-2, 6-0 win over Marton Fucsovics to reach the fourth round of the Australian Open on Friday.

The Italian needed three and a half hours to work his magic on his frequent practice partner from Hungary.

The 21-year-old winner had to change tactics to make his first career comeback from two sets to love down.

Sinner advanced into a contest against Stefanos Tsitisipas, at third the highest remaining seed in the field after early exits from top seed Rafael Nadal and No.2 Casper Ruud.

“The first two sets were tough for me,” sixth seed Sinner said. “I was feeling the ball well but missing a lot. My tactics were not so good.

“But I felt good physically in the fifth set, let’s see what happens in the next round.”

Sinner said that his strategy change was enough to see him through.

“I started with one tactic but had to change. I know his game very well, we are good friends.”

The Italian has reached Grand Slam quarter-finals four times and would make it a fifth should he win the next round.

Sinner, who has added Australian Darren Cahill on his coaching team, broke Fucsovics on four of 14 chances, ending with 31 winners and 52 unforced errors.

Tsitsipas dominated Dutchman Tallon Griekspoor 6-2, 7-6(5), 6-3 in just over two hours.

The Greek holds the edge over Sinner, winning their last four matches and standing 4-1 in the series; he beat Sinner here in the quarter-finals a year ago.

He won with an overhead smash on his third match point and has not lost a set so far at this edition.

“First crack of the whip,” Tsitsipas said of his initial match against Griekspoor.

“I mixed my shots well, opened up the court… my serving was exceptional (seven aces among 32 winners).

“There were not a lot of rallies on my serve, I played a clean match.

“I enjoyed fighting my way through, it was not easy at times.”

Tsitsipas said he feels confident going into the Sinner match.

“I have a good memory from last year. but I’m sure he’s much better prepared this time.

“I hope I can deliver a good level of game; it was close last time. It’s about maybe sticking to what worked previously, and continually sort of adding in the match.

“I have big weapons. I can, I think, generate even more power now than I did before. I have a lot of options out there.”

Sixth seed Felix Auger-Aliassime, who needed to pull off a comeback from two sets to love down in the previous round, had a somewhat easier test, defeating Argentine Francisco Cerundolo 6-1, 3-6, 6-1, 6-4.

The winner converted six of his 20 break points.

“I do feel my level is getting better,” the winner said. “Today was a good start.

“I’m happy with the way I stepped out on the court. I was playing my best tennis.

“Of course, there’s going to be a reaction from the opponent, which is normal. I’m happy that overall I found a good level today. It’s positive for what’s to come.”

The luck ran out for Mackenzie McDonald 48 hours after upsetting top seed Rafael Nadal; the American was humbled 7-6 (6), 6-3, 6-2 by Japan’s Yoshihito Nishioka in two and a half hours to end his unexpected Australian adventure.