Daniil Medvedev remains in contention for his first Australian Open title after dispatching local veteran John Millman in straight sets.
A wild first set included seven breaks of serve before Medvedev - the beaten finalist in each of the past two years at Melbourne Park - asserted his authority in a 7-5 6-2 6-2 victory.
It sets up a third-round clash with American Sebastian Korda, the 29th seed, who breezed past Japanese qualifier Yosuke Watanuki 6-2 7-5 6-4.
Medvedev's high-quality encounter with Millman on Wednesday night featured a series of long rallies, with the Russian later conceding he feared he might not be able to go the distance.
"Physically for both of us, it was tough," Medvedev said.
"One moment in the first set I wondered how I'm going to handle this.
"I was already pretty tired and just had to try to continue.
"Sometimes I cramp and sometimes I'm not strong enough to finish the matches, but this match I felt amazing physically."
It wasn't all smooth sailing for seventh seed Medvedev on Margaret Court Arena, where he had his serve broken three times by Millman in the first set.
But Medvedev was otherwise solid on serve, sending down 10 aces in a contest that lasted two hours and 19 minutes.
"It was a great match. The score in the second and third sets doesn't reflect everything that went on the court," Medvedev said.
"First set, he managed to break me three times.
"That's not that often that it happens, so I must be a little bit disappointed with myself.
"But he played amazing, so big credit to John."
Millman, who required a wildcard after falling to No.140 in the rankings, has twice been to the third round at his home slam - in 2016 and 2020.
The 33-year-old Queenslander saved two match points on his own serve in a fighting display before Medvedev served out the match.
The 2021 US Open winner is yet to drop a set at Melbourne Park this week.
