The pro-independence movement in Spain's richest region claimed victory in the crucial election which they vowed would lead to them declaring independence within two years despite Madrid's fierce opposition.
As the separatists celebrated in Barcelona to disco music and cries of "Independence!", rivals lined up to seize the initiative from the ruling Popular Party (PP) which took a battering in the vote, losing eight of its seats.
Regional president Artur Mas and his Together For Yes alliance won enough seats in the regional parliament to make an absolute majority if they team up with a radical left-wing group, the CUP.
But the two groups fell short of a majority of votes -- with a combined 1.9 million out of four million ballots cast.
That prompted Mas's opponents to dismiss as a failure his efforts to make the vote an indirect "plebiscite" on independence.
Pablo Casado, spokesman for Prime Minister Mariano Rajoy's PP, vowed the government would "continue to defend the unity of Spain".
The other big contenders in December's general election moved quickly to position themselves on the potentially destabilising issue of Catalan independence.
The leader of the main opposition Socialists, Pedro Sanchez, called on the region to "heal its wounds" and denounced what he called the "intransigence" of the PP in the dispute.
He congratulated the party that came second in the Catalan vote, the new centrist group Ciudadanos, hailing their shared support for reforms to answer separatist demands.
The two parties are jostling to oust the PP when Spain elects a new government in December.
Spain's left-wing protest party Podemos also leapt to cast the Catalan vote as a defeat for the PP, criticising its combative approach to the region.
"Only if our party governs in Spain can we build a country called Spain where there is also a place for a nation called Catalonia," said Podemos leader Pablo Iglesias.
Podemos and Ciudadanos have emerged over the past year as electoral contenders who polls show could carve up the vote, changing Spain's political landscape.
Podemos opposes Catalan independence but supports a full referendum on the issue.
Ciudadanos' leader Albert Rivera branded Sunday's vote a defeat for Mas, whom he dismissed as a relic of "old politics".
Albert Rivera celebrates his party achieving 25 seats Photo: AFP
Pushing on for independence
Rajoy had yet to react early Monday, but his party spokesman Casado argued Mas had "failed" by not winning a majority of votes.
"This election should serve to end the independence debate once and for all," Casado said.
But Together For Yes had vowed to declare independence by 2017 if it secured a majority in the parliament, even without a majority of votes.
First however Mas's alliance faces tough negotiations to strike an accord with CUP, an anti-capitalist citizens' movement for social justice, which does not want him to lead the separatist movement.
The CUP's lead candidate Antonio Banos on Sunday called for acts of civil disobedience against "unjust laws" to challenge the authority of the Spanish state in Catalonia.
Rajoy has vowed to uphold the law in the Catalan dispute.
"This creates a situation of great uncertainty," Narciso Michavila, director of the pollster GAD3, told AFP.
Together For Yes's lead candidate Raul Romeva put pressure on Madrid to negotiate over the secession drive, warning that its declaration of independence was inevitable.
"If the state shows no will to negotiate, we will do it anyway, because we have a mandate," Romeva told AFP.