Spain will meet Russia in the Hopman Cup final after the hopes of Czech Republic were dashed by Croatia on Thursday.
World number nine Mario Ancic's 7-6, 6-4 win over Czech Tomas Berdych meant Spain, who led India 2-0, could not be overtaken at the top of Group B.
Spain ended India's chances when Tommy Robredo and Anabel Medina Garrigues recorded singles wins. But a whitewash against Croatia could have helped the Czechs overtake the Spanish on set countback.
Lucie Safarova gave the Czechs a 1-0 lead by beating Sanja Ancic 7-5, 6-2 before her brother Mario downed world number 13 Berdych.
The night turned sour for India, who had won their first two matches and had only booked their place in the event by winning the inaugural Asian Hopman Cup in November.
Medina Garrigues showed superior movement from the back of the court to defeat Sania Mirza 3-6, 6-1, 6-3 while Rohan Bopanna had no answer to the pace of Tommy Robredo.
World number seven Robredo won 6-2, 6-3 to end India's hopes and shift the spotlight on to Ancic and Berdych.
Earlier, Russia booked their place in the final with a 3-0 whitewash of France.
TOP SEEDS
The top seeds, who lost their first match to Australia, started the day needing to win all three rubbers to overtake the French on countback at the top of Group A.
Nadia Petrova kept her end of the bargain by beating Tatiana Golovin 7-6, 6-0 before partner Dmitry Tursunov overcame Jerome Haehnel 6-1, 6-4.
The Russians then paired up to defeat the French duo 6-4, 6-2 in the mixed doubles.
"I'm very relieved because after our first match we didn't have any more chances," said Petrova in a courtside interview.
World number six Petrova triumphed despite receiving treatment for a strained side during the first set against Golovin.
Australia beat United States 2-1 in the dead second contest in the group.
Alicia Molik gave the hosts a 1-0 lead with a 3-6, 6-4, 6-4 win over Ashley Harkleroad before Mardy Fish levelled with a 7-5, 7-5 victory over Nathan Healey, a late replacement for the injured Mark Philippoussis.
The Australian duo then prevailed 6-4, 7-5 in the mixed doubles.
