Theresa May is to go back to Brussels to try to renegotiate the controversial Irish border backstop.
In a night of high drama at Westminster, DUP votes proved crucial in securing a proposal backed by the Prime Minister to reopen Brexit talks and replace the backstop with "alternative arrangements" to avoid a hard border.
But just minutes after the vote, EU leaders lined up to rebuff Mrs May.
They included Tanaiste Simon Coveney, who tweeted that the backstop "is necessary and tonight's developments at Westminster do nothing to change this".
DUP deputy leader Nigel Dodds said the votes of its 10 MPs had again made the difference and the House of Commons had now signalled what type of Brexit deal would command a majority.
But Brussels swiftly insisted that the Withdrawal Agreement would not be renegotiated regardless of how MPs voted.
The Irish government said the backstop couldn't be removed and Taoiseach Leo Varadkar is expected to speak with Mrs May today to discuss the outcome of the vote.
The Prime Minister is to go back to the EU to try to renegotiate her Brexit deal after MPs gave their backing to proposals to replace the controversial backstop.
They voted by 317 to 301 in favour of a proposal from Tory grandee Sir Graham Brady - backed by Mrs May - to reopen the Withdrawal Agreement and replace the backstop with "alternative arrangements" to avoid a hard border.
Mr Dodds tweeted afterwards that his 10 MPs' votes "make the difference... Again." SNP Westminster leader Ian Blackford said the Conservatives had "effectively ripped apart the Good Friday Agreement".
But the DUP deputy leader said it was "utterly reckless to talk in those terms".
Mr Dodds said: "This is a significant night because for the first time the House by majority has expressed what sort of deal will get through and will have a majority, and we will work with the Prime Minister to deliver the right deal for the UK."
Mrs May said the result showed there was a means of securing a "substantial and sustainable majority in this House for leaving the EU with a deal" and vowed to seek a new agreement with Brussels.
But in a statement, European Council President Donald Tusk said: "The Withdrawal Agreement is and remains the best and only way to ensure an orderly withdrawal of the UK from the European Union. The backstop is part of the Withdrawal Agreement, and the Withdrawal Agreementis not open for re-negotiation."
The European Parliament's chief Brexit negotiator, Guy Verhofstadt, said there was "no majority to re-open or dilute" the Withdrawal Agreement.
He tweeted: "Welcome the UK Parliament's decision to reject a no-deal & the hope of cross-party talks on future relationship. We stand by Ireland & the Good Friday Agreement
The House of Commons earlier approved a cross-party amendment, tabled by MPs Caroline Spelman and Jack Dromey, rejecting a no-deal Brexit by 318 to 310.
The vote is not legally binding on the Government but will impose massive political pressure on the Prime Minister to delay Brexit from its scheduled date of March 29 if she cannot secure a new deal from Brussels.
Ulster Unionist leader Robin Swann said: "After the votes in Westminster we still need to arrive at a deal that delivers for both the United Kingdom as a whole and Northern Ireland. We must now wait with interest to see what the EU says."
TUV leader Jim Allister said: "Parliament says the backstop must go. Good. Now let's have delivery. If there is no delivery, then, there must be no backsliding into accepting the Withdrawal Agreement still with the backstop. Instead, an unconditional exit on 29 March will be required if Brussels maintains its intransigence."
SDLP leader Colum Eastwood hit out at the Government's decision to "allow the dissolution of the Irish backstop" over the heads of people in Northern Ireland.
He said: "Tonight, London decided that the interests of the people in Northern Ireland were secondary to the needs of the Conservative Party. The rejection of the Irish backstop, the only viable mechanism to prevent a hard border on the island of Ireland, is an affront on the Good Friday Agreement.
"Let me be clear, the people of Northern Ireland did not consent to this. We will continue to engage with the Irish government to ensure that the backstop, as reiterated by Brussels, will not be undermined in the slightest."
Alliance deputy leader Stephen Farry said Parliament had voted to send Brexit down "a dead-end". He said: "Many people will be exasperated at a dysfunctional Parliament unable to process and work through the real choices facing the UK around Brexit. Thirty-one months on from the referendum there is still no coherent way forward.
"This is a pointless victory for the Government. The EU is rightly clear the backstop and the Withdrawal Agreement are not up for renegotiation, and have indicated as such once again today. So this represents a dead-end," Mr Farry added.
Another day. Another 7pm News Special. Another near-farce. Two long hours of divisions to produce the parliamentary equivalent of a scoreless penalty shoot-out. Still, at least the Commons will be able to vote again in a fortnight - presumably after Brussels has simply caved in and offered the Mother of Parliaments what it wants - except that Parliament still doesn't know what it wants.