World No.1 Novak Djokovic steered Serbia to the brink of the Davis Cup quarter-finals on Friday, easing past Belgian veteran Olivier Rochus on a makeshift court he described as the worst he's encountered.
Australian Open champion Djokovic needed just an hour and 39 minutes to beat 32-year-old Rochus 6-3 6-2 6-2 to give Serbia a 2-0 lead in their World Group first-round tie after Viktor Troicki had needed five sets to defeat David Goffin.
Twenty four hours earlier, Djokovic had lambasted the claycourt laid out over the parquet floor at the Spiroudome de Charleroi.
"It's the worst court I have ever played on. It's very, very dangerous," raged the world's top player.
But the International Tennis Federation claimed the court was playable, insisting they had laid 12 temporary claycourts on wood since 2009 without problems.
"It wasn't easy playing on clay after a long time indoors and coming from Australia quite late," said Djokovic.
"At the start, I had trouble with movement and getting used to the conditions but I managed to play my best tennis when I needed to."
Troicki battled back from two sets down against Goffin to win 1-6 3-6 7-6 (7-5) 6-4 6-4 as Serbia, the 2010 champions, eyed reaching the World Group quarter-finals for a fourth consecutive year.
Sam Querrey and John Isner powered the 32-time champion United States to a 2-0 lead over Brazil in Jacksonville, Florida.
Querrey fired 15 aces to beat Thomaz Bellucci 6-3 6-4 6-4 in the opener.
Isner, who missed the Australian Open with a knee injury, then pounded 32 aces past Thiago Alves in a 6-3 7-6 (7-4) 6-3 victory.
With the formidable doubles duo of Bob and Mike Bryan due up on Saturday, the United States looked to be in prime position to advance to face either Belgium or Serbia.
Spain, winners three times in the past five years, were on the ropes in Vancouver where Canada seized a 2-0 lead over the injury-depleted visitors, who were making do without Rafael Nadal, David Ferrer and Nicolas Almagro.
Milos Raonic had Canada off on the right foot with a 6-7 (5-7) 6-4 6-4 6-4 victory over Albert Ramos, and Canadian veteran Frank Dancevic needed just one hour and 48 minutes to beat Marcel Granollers 6-1 6-2 6-2.
The winner of the tie will face Italy or Croatia.
Marin Cilic gave Croatia a 1-0 lead in Turin with a 6-1 6-7 (6-8) 4-6 6-3 6-2 win over Paolo Lorenzi who had replaced flu-hit Fabio Fognini.
But Andreas Seppi pulled Italy level with a 6-2 6-7 (2-7) 6-4 6-4 win over Ivan Dodig.
France put one foot in the last eight when they took a 2-0 lead over Israel in Rouen in a tie which represented Arnaud Clement's debut as national coach.
Jo-Wilfried Tsonga, the world No.8, beat 173-ranked Amir Weintraub 6-3 6-3 4-6 7-5 before world No.10 Richard Gasquet breezed past Dudi Sela, ranked 106, 6-3 6-2 6-2.
Defending champions Czech Republic finished the day in Geneva at 1-1 against Switzerland.
Stanislas Wawrinka, the Swiss team's No.1 in the absence of Roger Federer, saw off Lukas Rosol, the shock conqueror of Rafael Nadal at Wimbledon last year, 6-4 6-3 6-4.
World No.6 Tomas Berdych then defeated Finland-born Henri Laaksonen.
The winners of that tie will meet either Kazakhstan or Austria in the last eight.
Argentina, who have lost all the three finals in which they have appeared, went 2-0 ahead against Germany in dramatic circumstances in Buenos Aires.
The winner will face France or Israel for a semi-final spot.