Serbia were stunned by an aggressive Indian outfit in their Davis Cup World Group first round clash on Friday, with the tie poised at 1-1.
The defending champions decided to rest star player Novak Djokovic for the encounter, but that decision nearly came back to haunt them when doubles specialist Rohan Bopanna pushed Viktor Troicki to five sets before the Serb eventually triumphed 6-3 6-3 5-7 3-6 6-3.
But India's Somdev Devvarman produced another surprise in the very next match, ousting the more fancied Janko Tipsarevic 7-5 7-5 7-6 (7-3) to leave the tie all square.
Spain's all-star team shot out to a 2-0 advantage over Belgium in Charleroi, with wins to world number one Rafael Nadal and Fernando Verdasco.
Nadal accounted for local hope Ruben Bemelmans 6-2 6-4 6-2, after Verdasco, who was filling in for late withdrawal David Ferrer, beat Xavier Malisse 6-4 6-3 6-1.
Last year's losing finalists France took a commanding 2-0 lead over Austria on away soil, as they failed to drop a set in the opening singles rubbers.
France's Jeremy Chardy swung the advantage his country's way with an upset 7-5 6-4 7-5 win over world number 10 Jurgen Melzer, before Gilles Simon crushed Stefan Koubek 6-0 6-2 6-3 to put Guy Forget's team one win away from overall victory.
Sweden took a 2-0 advantage over Russia in Boras, spearheaded by Robin Soderling, who demolished Igor Andreev 6-3 6-3 6-1 in the opening rubber.
Former world number nine Joachim Johansson, now ranked 749th in the world, then continued Sweden's momentum with an upset 6-3 7-6 (7-4) 6-4 win over Teymuraz Gabashvili to please the local fans.
Argentina went 2-0 up at home to Romania, with four-set wins to David Nalbandian and Juan Monaco.
Nalbandian struggled with a hernia injury, but sneaked past Adrian Ungur 6-3 6-2 5-7 6-4, before Monaco overcame Victor Hanescu 7-6 (7-5) 1-6 6-1 6-1.
Philipp Kohlschreiber earned Germany a hard-fought point when he overcame Croatia's Ivan Dodig in a five-set thriller 6-4 3-6 4-6 7-6 (8-6) 6-4, levelling the tie at 1-1 after Marin Cilic had earlier defeated Florian Mayer 4-6 6-0 4-6 6-3 6-1.
The United States' tie with Chile is evenly poised after Paul Capdeville fought back from two sets down to beat John Isner 6-7 (5-7) 6-7 (2-7) 7-6 (7-3) 7-6 (7-5) 6-4.
Earlier, Andy Roddick had given new captain Jim Courier a dream start by beating Nicolas Massu 6-2 4-6 6-3 6-4 in the opening rubber.
World number seven Tomas Berdych ensured the Czech Republic would be level 1-1 with Kazakhstan with his 7-6 (7-5) 6-2 6-3 win over Mikhail Kukushkin after Andrey Golubev had earlier defeated Jan Hajek in five sets.