Key Biscayne, FL (SportsNetwork.com) - Former world No. 1 stars Novak Djokovic and Roger Federer were a pair of second-round winners Friday at the $4.7 million Sony Open, the second straight ATP Masters 1000 event.

The second-seeded Djokovic handled France's Jeremy Chardy 6-4, 6-3, while the fifth-seeded Federer foiled 6-foot-10 Croat Ivo Karlovic 6-4, 7-6 (7-4). Karlovic popped 13 aces in a losing effort.

Djokovic beat Federer in last week's marquee finale at Indian Wells.

The Serbian stalwart Djokovic is a three-time Miami champion and former runner-up, while the Swiss icon Federer owns two Miami titles and is also a former runner-up.

Playing his first match in three weeks, fourth seed David Ferrer reached the round of 32 by handling Russian Teymuraz Gabashvili 6-4, 6-0, while ninth- seeded Frenchman Richard Gasquet topped Colombian Alejandro Gonzalez 7-6 (9-7), 6-4 on the hardcourts at Crandon Park. The French Open runner-up Ferrer was last year's Miami runner-up to Wimbledon champion Andy Murray.

Rising 15th-seeded Bulgarian Grigor Dimitrov dismissed Spaniard Albert Montanes 6-1, 6-7 (5-7), 6-3, while 16th-seeded Spaniard Tommy Robredo snuck past qualifier and promising Austrian Dominic Thiem 6-4, 7-6 (10-8).

Meanwhile, 17th-seeded South African Kevin Anderson leveled Argentine Horacio Zeballos 6-4, 6-3, 30th-seeded German Florian Mayer dropped Croat Ivan Dodig 6-3, 6-2, and 31st-seeded Italian Andreas Seppi outlasted Czech veteran Radek Stepanek 7-6 (10-8), 4-6, 6-4. Mayer's third-round opponent will be Djokovic.

The 2014 winner of this lucrative event will collect $787,000.