Melbourne Park's first glimpses of Andy Murray and Rafael Nadal were brief on Tuesday but Serena and Venus Williams both gave full value at the Australian Open with their first round wins.
Pre-tournament favourite Murray zipped through to round two in double-quick time when his opponent retired injured.
The fourth seed was leading Andrei Pavel 6-2, 3-1 when the Romanian quit after 45 minutes with a back injury that had kept him out of the sport for most of last year.
"I guess if you want to do well in the tournament, it's good to conserve some energy ... hopefully that was a good thing," the Briton said, weighing the pros and cons of his short outing in 37 degree Celsius heat. Next up for him is Marcel Granollers.
World number one and top seed Nadal took just 32 minutes longer to thrash Belgian Christophe Rochus 6-0, 6-2, 6-2 in the night match.
The Spanish muscleman won 83 points to Rochus' 40 -- including 47 clean winners to seven in a dominant display.
"I played well, moving the ball very well around the court. The only thing you think is 'win'. It was quick so that was better," he said.
Nadal, whose best performance at the Australian Open was when he reached the semi-finals last year, faces Roko Karanusic of Croatia in the next round.
Serena cantered through with a 6-3, 6-2 win over China's Yuan Meng. The American second seed is seeking a fourth Australian title after winning here in 2003, 2005 and 2007.
"It was a little hot for me today," she smiled, sipping a drink. "It was a case of taking my time, not giving 1,000 percent, you know?
"I was getting super thirsty out there -- at one stage I had to stop and have a drink of water.
"It was definitely extreme conditions," she added, stifling a sniffle. "I do have a little bit of a head cold ... I hope that goes away."
Serena was joined in the second round by big sister Venus who enjoyed a 6-3, 6-3 victory over Germany's Angelique Kerber.
Sixth seed Venus is still seeking a first singles title at Melbourne Park despite having five Wimbledon and two US Open crowns to her name.
"Yeah, I'm in the second round. Definitely was the goal," the reigning Wimbledon champion mused. Next up for her is Carla Suarez Navarro.
World number four Elena Dementieva survived the heat to see off Kristina Barrois. Unbeaten so far this year after picking up titles in Auckland and Sydney, Dementieva beat the German 7-6, 2-6, 6-1.
"It was a very tough match, especially because of the weather conditions today. Also it was not easy for me to come here after playing so many matches in a row," the blonde Russian said.
"I'm sure I wouldn't have minded one or two extra days before. But those are the kind of days you have to survive. I'm just very glad I was able to do it."
She will next play Iveta Benesova.
Last year's men's runner-up Jo-Wilfried Tsonga was on song, beating Juan Monaco 6-4, 6-4, 6-0. "I played without pain," he said, referring to a recent back injury. "So it was a nice match. That's it."
Former world number one Lleyton Hewitt suffered a drawn-out agonising exit from his home Grand Slam when he was beaten 5-7, 6-2, 6-2, 3-6, 6-3 by Chilean 13th seed Fernando Gonzalez.
It was Hewitt's first opening round defeat at the Australian Open since 2002, when he was suffering chicken pox.
Finalist at Melbourne Park four years ago, Hewitt slid down the rankings after undergoing hip surgery last August and only returned to competition this month.
"I'll probably look back at it in a couple of days' time, look at where I could have improved and whatever," the world number 70 said.
"But in hindsight, when you haven't had the matches, haven't played five sets for quite a while, you're always going to be fighting it a little bit."