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 took five sets to defeat David Goffin.
Twenty-four hours earlier, Djokovic had lambasted the clay court 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 said that the court was playable, insisting that they had laid 12 temporary clay courts 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 their 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 last 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 got 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 either 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 took a commanding 2-0 lead over Israel in Rouen as Arnaud Clement made his debut as national coach.
Jo-Wilfried Tsonga, the world number eight, beat Amir Weintraub 6-3, 6-3, 4-6, 7-5 before world number 10 Richard Gasquet breezed past Dudi Sela 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 number one in the absence of Roger Federer, saw off Lukas Rosol, the shock conqueror of Nadal at Wimbledon last year, 6-4, 6-3, 6-4.
World number six Tomas Berdych then defeated Finland-born Henri Laaksonen 6-3, 6-2, 6-7 (5/7), 6-1.
The winners of that tie will meet either Kazakhstan or Austria in the last eight.
Kazakhstan led 2-0 after the opening day in Astana with Andrey Golubev beating Andreas Haider-Maurer 7-6 (7/2), 6-3, 7-6 (7/5) and Evgeny Korolov seeing off the experienced Jurgen Melzer 7-6 (7/4), 6-3, 6-2.
Argentina took a 2-0 lead over Germany in dramatic circumstances in Buenos Aires.
Carlos Berlocq claimed the first point when Philipp Kohlschreiber was forced to quit in the final set because of a thigh injury with the score standing at 3-6, 7-5, 2-6, 6-4, 4-5.
Argentina, playing without Juan Martin del Potro, took a firmer grip when Juan Monaco got past Florian Mayer 6-7 (4/7), 6-3, 6-3, 6-4.
AFP
