Juan Martin del Potro remained on course for a ‘Sunshine Double’ after claiming the BNP Parisbas Open title last week.
The Argentine proved too strong for Japan’s Kei Nishikori as he eased past the 26th seed with a 6-2, 6-2 victory to advance to the Round of 16 in Miami.
The win which is Del Porto’s 13th on the trot, lasted only 72 minutes and spells a brilliant start to the 2018 season for the man from Tandil.
Del Potro will now face Filip Krajinovic in the Round of 16. Krajinovic was on fire against Benoit Paire, who had earlier beaten Novak Djokovic, as he scored a comfortable 6-3, 6-3 win in 70 minutes.
After Federer’s shock exit to qualifier Thanasi Kokkinakis on Saturday, second seed Marin Cilic is the highest remaining seed left in the competition and he remained on course for a big-hitting semi-final showdown with fellow former US Open champion Del Potro.
Cilic was tested by Canada’s Vasek Pospisil, who saved three match points, before sealing a 7-5 7-6 victory that takes him into the Round of 16 in Miami for just the third time in his career.
South Korean sensation, Hyeon Chung, who’s yet to drop a set in Key Biscayne so far, whitewashed Saudi Arabian-born Michael Mmoh 6-1, 6-1 to also join the Round of 16 train.
Grigor Dimitrov, meanwhile, fell 6-4, 6-4 to unseeded Frenchman Jeremy Chardy.
In the women’s field, world no. 4 Elina Svitolina rallied from an opening set loss to rattle Daria Gavrilova 4-6, 6-0, 6-1, securing a Round of 16 berth.
Venus Williams claimed a hard fought 5-7, 6-3, 7-5 victory over Kiki Bertens. For a quarterfinal spot, Venus, 37, will square off against defending champion Johanna Konta, who dismantled Belgium’s Elise Mertens 6-2, 6-1.