Debuts on home turf don't come much more emphatic than a teenage Denis Shapovalov's against the might of Rafael Nadal.
Cap on backwards with swagger to boot, an upset of the top seed more than four years ago only backed up an inner-belief, further enhanced after testing Novak Djokovic in a maiden Grand Slam semifinal appearance at the All England Club last July.
Denis Shapovalov  v Alexander Zverev 
Through to the second week at a major for just the fourth time, Shapovalov will meet third seed Alexander Zverev on a stacked Sunday, which also includes Nadal, a resurgent Gael Monfils and seventh seed Matteo Berrettini in action.
Shapovalov's ascent since that watershed 2017 upset of Nadal has not unfolded quite as rapidly as some had predicted.
It was easy to forget, however, Shapovalov was still only 22 and while gifted with unbridled flair, he was hard at work adding another crucial element to his skillset: "the Rafa mentality."
"Just fighting for every point, kind of just staying in it, not letting things bother you," Shapovalov said. "I think Rafa is such a great competitor. I mean, he really makes you earn every single point against him. It's definitely something I'd like to get to."
The 14th seed would do well to channel Nadal's fighting qualities when he squares off against Zverev for a shot at his first Australian Open quarterfinal.
The German holds a 4-2 advantage on that ledger, including their most recent encounter, a deciding-set tiebreak thriller in last year's ATP Cup in Melbourne.
Zverev, who reached the last four at Melbourne Park two years ago, has had a considerably easier time of it through the opening three rounds, too.
Yet to drop a set, he has spent just six hours and 37 minutes in battle, while Shapovalov has dropped at least a set in each round in 11 hours on court.
"First meeting for us at a Slam but we actually played on Rod Laver Arena in an ATP Cup match (in 2021) but he's playing well," Zverev said.
"I think today's match was a very high level from him and we're both going to be happy we're in the second week. Hopefully I can win of course but it's going to be a great match."
Rafael Nadal  v Adrian Mannarino
Shapovalov's idol, Nadal, continues his quest for a record 21st major at Melbourne Park on Sunday when he faces fellow southpaw Adrian Mannarino.
The Spaniard dropped his first set of the tournament against 28th seed Karen Khachanov on Friday night but finished at his brutal best to move into the fourth round for the 15th time.
Mannarino continued his seed-slaying run against last-year's semifinalist Aslan Karatsev, having already beaten 10th seed Hubert Hurkacz and was seeking his first victory over Nadal in three attempts.
"Mannarino is playing great. I think the match against Hubert (was) a surprise," Nadal said. "He was playing at, I think, a very high level.
"To win against a player like Hubert in straight sets with that result is because you did a lot of things well."
Gael Monfils  v Miomir Kecmanovic
A first-round departure at the Australian Open last year, his sixth straight defeat, left a disconsolate Monfils seriously questioning his future.
But a title run in Adelaide to start 2022 had worked wonders in restoring the Frenchman's confidence.
Through to the fourth round at Melbourne Park for the fifth time, the former world No.6 meets Serbian Miomir Kecmanovic, a player he defeated indoors in Paris last year.
In Novak Djokovic's absence, the 22-year-old Kecmanovic has made the most of his draw opening, defeating 25th seed Lorenzo Sonego on Friday for his maiden second-week berth at a major.
"For sure it's going to be difficult. He's been playing well," Kecmanovic said of facing Monfils. "But I've also played really good and have this momentum going, so hopefully it will be enough to take me through."
Matteo Berrettini  v Pablo Carreno Busta 
After emerging victorious from a four-hour, 13-minute epic against rising teenager Carlos Alcaraz, seventh seed Berrettini looks to back it up against another Spaniard, Pablo Carreno Busta.
Neither has passed the fourth round at Melbourne Park before in what will be a first-time meeting between the two.
The 19th seed Carreno Busta comes off a four-set triumph over highly regarded American prospect, Sebastian Korda.
"It's gonna be an interesting one. He's a really solid player... He likes to play here in Australia," Berrettini said. "I think he's a really good player on hard (court)…
"I'm feeling confident. I think the level today was really high and I'm getting better and better."