Rafael Nadal and Iga Swiatek face stern but vastly different early tests as the respective men's and women's top seeds headline the day-one Australian Open action in Melbourne.
Winless in two matches at the season-opening United Cup in Sydney, Nadal won't have the luxury of easing into his Open title defence against rising British star Jack Draper.
Draper, at a career-high 38th in the world after an impressive start to the summer, is among the most dangerous unseeded players in the draw, as the likes of top-10 heavyweights Stefanos Tsitsipas and Felix Auger-Aliassime know too well after succumbing to the 21-year-old last season.
"Probably one of the toughest first rounds possible, being seeded. Young, powerful, growing very, very fast on the ranking, playing well," Nadal said of his challenger.
"A big challenge for me at the beginning to start the tournament. Let's see. I'm here to just give myself a chance.
"I know he's playing well. He has a lot of positive things, and probably a great career in front.
"I hope to be ready to fight for that first round and let's see what can happen."
A victor just once in his past six matches, the great Spaniard needs to emerge from a rut that may explain why men's tennis's most prolific major winner surprised onlookers when he hurled his racquet, most un-Nadal like, into the court in frustration during practice on Friday.
"I don't know if I had in the past those results," said the 22-time grand slam champion.
"(But) that's part of our journey. You need to live with your personal momentum. My personal momentum is not bad, I tell you. I am good and happy. I'm practising well.
"Then I need to win a couple of matches. If that can happen here - I hope."
Nadal's vanquished 2022 final opponent Daniil Medvedev is another big name in action on Monday.
Runner-up also in 2021, to Novak Djokovic, Medvedev is somewhat flying under the radar entering his first-round meeting with American Marcos Garon after tumbling from world No.1 to eighth.
Seeded seventh, the Russian is projected to face Nadal in the quarter-finals.
Jason Kubler, John Millman and Rinky Hijikata are the only Australian men playing on Monday, with seeded big guns Nick Kyrgios and Alex de Minaur starting on Tuesday.
Swiatek, the reigning French and US Open champion and bidding for the third leg of a career grand slam, launches her title quest against German Jule Niemeier.
The Polish world No.1 ousted the 68th-ranked Niemeier from the US Open in September in their only previous encounter.
But after withdrawing from the Adelaide International 2 with a shoulder problem, and being thumped by world No.3 Jessica Pegula in her most recent outing at the United Cup, Swiatek's fitness will be under the microscope on Rod Laver Arena on Monday night.
Pegula, triumphant United Cup US teammate Madison Keys, last year's Open runner-up Danielle Collins, fellow American seed Coco Gauff and Wimbledon champion Elena Rybakina also feature on day one.
Wildcards Olivia Gadecki, Storm Hunter and Talia Gibson will fly the Australian flag.
