LONDON (Reuters) - France and Serbia both sealed quickfire victories to reach the Davis Cup quarter-finals but top seeds Spain were hanging on by their fingernails against Canada ahead of Saturday's doubles.
French duo Julien Benneteau and Michael Llodra thrashed Israel's Dudi Sela and Jonathan Erlich 7-6 6-1 6-0 in Rouen to give France a 3-0 lead that rendered Sunday's reverse singles meaningless.
Jo-Wilfried Tsonga and Richard Gasquet both comfortably won their singles matches on Friday.
World number one Novak Djokovic will be spared more exertion on Sunday after 2010 winners Serbia built a 3-0 lead against Belgium when Viktor Troicki and Nenad Zimonjic came through in four sets against Steve Darcis and Ruben Bemelmans.
Djokovic, playing his first match since winning the Australian Open for a third consecutive year, crushed Olivier Rochus on Friday on an indoor claycourt in Charleroi.
France, bidding for a 10th Davis Cup title, will face either Germany or Argentina in the quarter-finals while Serbia will be waiting for either the United States or Brazil.
Argentina and the U.S. are both leading 2-0 ahead of Saturday's doubles action.
A weakened Spain must win Saturday's doubles rubber to avoid a shock defeat against Canada in Vancouver after the hosts moved 2-0 ahead with victory in the opening singles.
Elsewhere, Austria kept their tie against Kazakhstan alive as Julian Knowle and Alexander Peya won the doubles to leave the hosts leading 2-1 in Astana.
Saturday's doubles matches could prove pivotal for the two other ties, with Italy and Croatia and Switzerland and holders Czech Republic both level at 1-1.
(Reporting by Martyn Herman, editing by Stephen Wood)