Melbourne - Seven-time champion Serena Williams swings back into Australian Open action on Thursday against Eugenie Bouchard while six-time winner Novak Djokovic turns back the clock in a clash with Jo-Wilfried Tsonga.
In her first tour match since losing an US Open final mired in controversy, Williams delivered an ominous warning in a 49-minute opening round thrashing here of Tatjana Maria.
Next in the firing line is Canadian Bouchard. They have met twice before, but not since 2014, with the American winning both times.
Williams, who is bidding to match Margaret Court's record of 24 Grand Slam crowns on her first return to Melbourne Park since winning in 2017, cited her consistency and few unforced errors as key takeaways from her first round outing.
Despite 2014 Wimbledon finalist Bouchard slipping down the rankings to 79, she said she was not taking her lightly.
"It will be a great match. She plays really well. She does everything well, and I really like that she doesn't quit," she said of the popular Canadian, who she meets on Rod Laver Arena in a night match.
"You know, people write her off, and she doesn't let that bother her. She continues to fight and do what she needs to do. I think that's really good."
Djokovic, gunning for a record seventh title, has a fairytale meeting with Frenchman Tsonga in a rematch of their 2008 final that the Serb won.
"It's funny. I mean, 11 years after our first Grand Slam final here, it feels like a lot has happened for both of us," said Djokovic.
"He also struggled with injuries lately. It's good to see him playing well. It's good to see him back."
World number one Simona Halep, who narrowly survived a three-set first-round scare, tries to get her tournament back on track against American Sofia Kenin, who won the warm-up Hobart International.
"I have no expectations because I'm not at the highest level," said the Romanian, who is returning from injury. "But I'm motivated."
Venus Williams is also in action as she looks to re-live past glories, taking on France's Alize Cornet, while fourth seed and US Open champion Naomi Osaka has a clash with Slovenia's Tamara Zidansek.
Men's fourth seed Alexander Zverev, who beat Djokovic to win the ATP Finals at the end of last season, takes on Jeremy Chardy, a Melbourne quarter-finalist in 2013.