Roger Federer and Novak Djokovic were untroubled, but Grigor Dimitrov was among five seeds to fall at the Australian Open on Wednesday.
Federer produced an excellent performance in a straight-sets thrashing of Filip Krajinovic on Rod Laver Arena.
The Swiss great had received good news before even going on court after three seeds fell in his quarter of the draw, with Fabio Fognini only narrowly avoiding that fate.
Earlier, Djokovic dropped just seven games on his way to a thrashing of Tatsuma Ito in Melbourne.
FEDERER, DJOKOVIC EASE THROUGH
Having lost a set in the opening-round victory over Jan-Lennard Struff, Djokovic suffered no such setback against Ito, winning 6-1 6-4 6-2.
A record seven-time champion in Melbourne and 16-time grand slam winner, Djokovic brushed past Ito on the back of 31 winners.
Federer was even more impressive later in the day, crushing Djokovic's Serbian compatriot Krajinovic 6-1 6-4 6-1.
The 20-time grand slam champion looked in fabulous form with 42 winners and just 14 unforced errors, reaching the third round in Melbourne for the 21st straight year.
Federer will next face John Millman, who upset 31st seed Hubert Hurkacz 6-4 7-5 6-3. The Australian stunned Federer at the US Open in 2018.
DIMITROV AMONG SEEDS TO CRASH OUT
Dimitrov, a semi-finalist in 2017, bowed out in a surprise 6-4 7-6 (8-6) 3-6 6-7 (3-7) 7-6 (10-3) loss to Tommy Paul.
The Bulgarian 18th seed went up by a break twice in the final set, but lost seven consecutive points from 3-3 in the match tie-break.
Matteo Berrettini, the eighth seed who reached the US Open semi-finals, was edged out by Tennys Sandgren 7-6 (9-7) 6-4 4-6 2-6 7-5.
Sandgren reached the quarter-finals in 2018 and will face Sam Querrey in an all-American third-round clash.
British 30th seed Dan Evans also made a second-round exit, losing to Djokovic's next opponent, Yoshihito Nishioka, 6-4 6-3 6-4.
CILIC, RAONIC ADVANCE AS TSITSIPAS GETS FREE PASS
Marin Cilic, runner-up in 2018, eliminated 21st seed Benoit Paire in a thriller.
The Croatian needed three hours, 33 minutes to overcome Paire 6-2 6-7 (6-8) 3-6 6-1 7-6 (10-3).
Next up for Cilic is a man he has lost to twice at the Australian Open in Roberto Bautista Agut, the Spanish ninth seed too good for Michael Mmoh 5-7 6-2 6-4 6-1.
Milos Raonic has reached at least the Australian Open quarter-finals four times and the Canadian has shown impressive form early on this year.
The 29-year-old served 19 aces in a 6-3 6-4 6-2 victory over Cristian Garin on Wednesday and next faces 2019 semi-finalist Stefanos Tsitsipas.
Tsitsipas advanced without hitting a ball after Philipp Kohlschreiber withdrew due to a muscle strain.
FOGNINI TAKEN THE DISTANCE BY THOMPSON
It is proving to be an arduous campaign for Fognini, who surrendered a two-set lead before holding his nerve in a decisive tie-break with home hope Jordan Thompson.
The Italian was taken the distance in his first-round meeting with Reilly Opelka after losing the first two sets, and this time it was the 12th seed who almost choked on a healthy lead.
Fognini hurt himself when punching his racket in frustration and was called for a foot-fault in the fifth-set breaker, but he got the job done in a memorable 7-6 (7-4) 6-1 3-6 4-6 7-6 (10-4) triumph that took more than four hours to complete.