Roger Federer and Novak Djokovic opened with straight-set wins Friday at the WTA and ATP Miami Masters while Andy Murray rallied to win his first match since splitting with coach Ivan Lendl.
Five days after facing off in the Indian Wells final, Federer and Djokovic produced solid triumphs to reach the third round after first-round byes.
Two-time Miami champion Federer played steady, controlled tennis for a 6-4, 7-6 (7/4) victory over Croatian Ivo Karlovic.
Serbian second seed Djokovic, winner of the Indian Wells trophy over his Swiss rival last weekend, eased past Jeremy Chardy, 6-4, 6-3.
Britain's Murray broke the last six service games of Australian Matthew Ebden for a 3-6, 6-0, 6-1 triumph to advance.
The sixth-seeded Scotsman lost his way in the opening set after missing on several chances but quickly recovered poise over the remainder of a late evening.
The defending champion, who trains nearby, will next face Spain's Feliciano Lopez after ending with 28 winners and 33 unforced errors.
"I had a poor start but this is a good win to get," Murray said. "I have a lot to work on in my game but I'm glad to get through."
Murray also said he will wait until after next month's Davis Cup tie to decide about a new coach.
"I will take my tine on that decision," Murray said. "After Davis Cup, I have a month without tournaments so I can give it some thought."
France's Chardy delayed the inevitable ahead of the final game against Djokovic, taking a medical timeout after hobbling to a courtside entry tunnel with an ankle problem.
As Djokovic fidgeted with practice serves, Chardy returned to take his medicine, with the three-time champion Serb advancing with three aces in the concluding game.
"He twisted his ankle,"Djokovic said. "I talked with him after the match. He's still in physio room, so he says it's not as bad as he thought. But I wish him recovery."
Fifth seed Federer, now 11-1 all-time against Karlovic, was impeccable in the opening set, losing his only point on serve as he stood 5-4, 40-0 moments before serving out the opener.
A winning tie-break in the second finally made the difference for Federer, now 42-12 in Miami with titles in 2005 and 2006.
"I made sure I had a lot of first serves in, made sure I stayed aggressive from the baseline," said the Swiss. "I think it worked really well, hardly any unforced errors.
"I was able to move Ivo around, and I was able to maintain that throughout the match, which was key. I could focus a bit on returning while then holding serve, which is important against Ivo."
Federer missed the tournament a year ago as he rested with back pain but has turned his 2014 season around after a low-key 2013.
He withstood 13 aces from the big-hitting Croatian in the 74-minute win.
Spanish fourth seed David Ferrer made a winning comeback after missing Indian Wells with injury, defeating Teimuraz Gabashvili 6-4, 6-0
Li wins in walkover
China's Li Na reached the third round on the women's side as intended opponent Alisa Kleybanova withdrew with viral illness before their match.
The result sends the second seed into a contest against American Madison Keys who beat Daniela Hantuchova 6-4, 6-2.
Two seeds lost in upsets as American Varvara Lepchenko put out seventh seeded Jelena Jankovic 6-3, 2-6, 7-6 (7/2) and Czech Barbora Zahlavova Strycova beat number 13 Italian Roberta Vinci, 6-4, 2-6, 7-5.
Australian Open runner-up and 10th seed Dominika Cibulkova defeated Yvonne Meusburger 6-1, 6-2.
Elina Svitolina won her third match over Australian Open semi-finalist Eugenie Bouchard, the 18th-seed, 1-6, 6-1, 6-2 after losing to the Canadian in the 2012 junior Wimbledon final.
France's Alize Cornet beat Andrea Petkovic 6-2, 6-7 (0/7), 6-4 as the frustrated German drop-kicked a racquet some considerable distance during a moment of anger.