Top seeds Novak Djokovic and Simona Halep advanced to the Australian Open third round on Thursday but Halep was made to work hard for her win over American Sofia Kenin.
Djokovic produced a clinical display to put away Frenchman Jo-Wilfried Tsonga 6-3 7-5 6-4 in a repeat of the 2008 final at Melbourne Park.
It was the 31-year-old Serb's 16th consecutive win on the Grand Slam stage and he will next face Canadian youngster Denis Shapovalov.
Halep was cruising to victory after leading by a set and a break but Kenin roared back to edge the second set in a tiebreak.
Despite going down a break in the decider, Halep kept her composure to prevail 6-3 6-7(5) 6-4.
It is the first time since Wimbledon in 2009 that all of the women's top eight seeds have reached the third round at a Grand Slam.
Serena Williams needed just 70 minutes to swat aside Canada's Eugenie Bouchard 6-2 6-2 as she continued her quest for a record 24th Grand Slam title.
Twice Grand Slam winner Garbine Muguruza overcame Britain's Johanna Konta 6-4 6-7(3) 7-5 in a marathon match that finished after 3am local time having started after midnight.
The Spaniard will next face two-times finalist Venus Williams.
"I can't believe that there's people watching us at 3:15," Muguruza said courtside.
"It was very tough. Johanna was playing very good, serving incredibly, big shots. I just tried to fit and hang in there.
"We play for you guys watching, otherwise why are we here. "I'm going for breakfast now!"