(CNN) -- Mardy Fish kept alive American hopes of victory in the Sony Ericsson Open in Miami on Sunday, beating Frenchman Richard Gasquet in straight sets to reach the last 16 of the event.
Fish, seeded 14th, is the highest-ranked home player remaining following the elimination of defending champion Andy Roddick, and he never looked in danger of following his compatriot out of the tournament, winning 6-4 6-3 in 91 minutes.
However, the route to the quarterfinals looks a tricky one for Fish, with either fourth seed Robin Soderling or former U.S. Open champion Juan Martin del Potro awaiting in the next round.
"First thing that comes to mind is underdog, which is probably what I'll be," Fish told the official ATP Tour website.
"Juan seems to be back to his normal self and Robin has three titles this year and is playing as well as anyone, so it will be tough."
In other matches, Spanish sixth seed David Ferrer cruised to a comfortable 6-4 6-2 win over India's Somdev Devvarman while 30th seed John Isner saw off Alex Bogomolov 6-2 7-6.
Meanwhile, in the women's tournament, French Open champion and fifth seed Francesca Schiavone reached the last 16 with a 6-4 7-6 victory over Lourdes Dominguez Lino.
Ninth seed Agnieszka Radwanska is also through, after winning a tricky last 32 clash with Russian 24th seed Maria Kirilenko 7-6 6-3.
Indian Wells semifinalist Marion Bartoli, seeded 15th, crushed Ekaterina Makarova 6-0 6-2 while former world No.1 Ana Ivanovic also advanced after Virgine Razzano of France was forced to retire through injury.