Novak Djokovic and Tomas Berdych booked their spots in the Miami Open third round, although the latter did so without hitting a ball.
Djokovic did what was expected of him against Kyle Edmund as the two-time defending champion and world number one cruised through at the ATP 1000 event.
Berdych progressed without taking to the court, while Marin Cilic, Richard Gasquet and David Ferrer also advanced.
Djokovic was the man to watch on Friday in his first appearance at a tournament he has won five times, with Roger Federer having withdrawn before his match against Juan Martin del Potro.
DJOKOVIC CRUISES, BERDYCH GETS WALKOVER
Serbia's Djokovic had few troubles against Edmund before completing a 6-3 6-3 win in just 80 minutes.
He was dominant on serve and that allowed him to attack when returning, breaking four times.
Berdych was due to face Rajeev Ram in the second round, but the American withdrew due to illness.
There was better news for Cilic, the Croatian 11th seed easily getting past Dusan Lajovic 6-4 6-1.
French 10th seed Gasquet beat Albert Ramos-Vinolas 6-4 6-4, while Ferrer was challenged early before overcoming Taylor Fritz 7-6 (8-6) 6-1.
Federer and Del Potro were set to meet, but the Swiss great withdrew due to illness - leaving the Argentinian to suffer a 6-4 6-4 loss to countryman Horacio Zeballos.
LOPEZ, CHARDY OUT
Only three seeds were upset in the men's draw on Friday.
Spaniard Feliciano Lopez went down to fellow left-hander Yoshihito Nishioka 6-4 6-4, while Jeremy Chardy was beaten by Fernando Verdasco 6-4 6-4.
Guillermo Garcia-Lopez, the Spanish 32nd seed, was a 6-2 6-4 loser to Lucas Pouille.
Alexander Zverev served 14 aces, but the German suffered a 7-6 (11-9) 7-6 (7-3) loss to Steve Johnson.
Viktor Troicki saved four match points before edging past Inigo Cervantes 6-7 (6-8) 7-6 (11-9) 7-6 (7-3).
"I have not felt great for a few days and unfortunately it got worse in the last 24 hours," Federer said, explaining his withdrawal.
NADAL, MURRAY EYE PROGRESS
Rafael Nadal and Andy Murray are in action on Saturday, taking on Damir Dzumhur and Denis Istomin respectively.
Stan Wawrinka, Milos Raonic, Grigor Dimitrov and John Isner will also be looking to advance.