Serena Williams knows she must be at her tenacious best to join sister Venus in the Australian Open semi-finals, with a confident Johanna Konta determined to crash the party on Wednesday.
The American's unrelenting quest for a record 23rd Grand Slam title to surpass Steffi Graf and return to world number one was tested by Barbora Strycova in round four, and Konta won't be any easier.
The British ninth seed has set herself up as a genuine title contender with an impressive nine-match unbeaten streak after winning this month's Sydney International.
At stake is a semi-final with either comeback queen Mirjana Lucic-Baroni or fifth seed Czech Karolina Pliskova, with Venus Williams and fellow American Coco Vandeweghe contesting the other.
Williams, chasing her seventh Australian title, is aware of the danger posed by Konta.
"I have watched her game a lot. She's been doing really, really well, and she hasn't lost yet this year," she said.
"She has a very attacking game. I know her game pretty well. I look forward to it."
"I have absolutely nothing to lose in this tournament," added the second seed. Everything here is a bonus for me. Obviously I'm here to win."
Her coach Patrick Mouratoglou said that to counter Konta's lightning fast game, Williams, who can retrieve the top world ranking is she wins the final, needed to start moving better around the court.
"We have to solve that, especially against Konta, who is someone who plays so fast, so aggressive, takes the ball early. You can't afford to be slow," he said, the Herald Sun reported.
"It was not that she won Sydney but it was also the way that she won it. She has no doubts at the moment."
Like many players Sydney-born Konta, who has blossomed over the past two years, making the semi-finals in Melbourne last year, used to watch Williams as a child growing up.
She said it will be an honour to be on the same court, but she won't be overawed in her first career meeting with the American great.
"I'm really looking forward to the challenge, and I'm looking forward to being on court, out on court with her and competing against her," she said.
"Just the amount of experience she has, I'm sure she's got her system and her method for preparing for every match, regardless who she plays, and I'm sure she's going to be applying that method against me."
Preceding them on Rod Laver Arena will be Lucic-Baroni and Pliskova.
Lucic-Baroni, who was making waves as a teenage prodigy when the Williams sisters were emerging in the late 1990s, is in her first Grand Slam quarter-final in 18 years.
She is looking to keep her fairytale comeback on track against a player who made the US Open final last year.
"I'm still here. I'm still fighting," said the 34-year-old, who was a Wimbledon semi-finalist in 1999 aged 17 before personal difficulties forced her out of the game for years.
The Croat beat third seed Agnieszka Radwanska en-route to the quarter-finals and Pliskova, last year's US Open finalist, is wary of the threat she poses.
"Definitely, she's playing really well here," she said.
"These conditions probably suit her as well. She has to be playing well when she's in the quarter-finals. I just going to expect tough match. I have to be ready.
"It's going to be probably a fast game, not many rallies. So I have to be really ready on my legs, serving well. I think I have good chance."