Parliamentarians threw out a no-confidence motion put forward by the opposition Labour Party a day after May's humiliating defeat on the Brexit deal she negotiated with the EU.
But the implications of the latest vote could ultimately prove to be greater for Labour - whose leadership has placed its bets on unseating her "zombie government" and engineering a general election - by reviving its own demons over Europe.
Professor Anand Menon, director of the think-tank, The UK in a Changing Europe, said: "All those Labour backbench MPs who to date have hidden behind the slogan 'I want a general election' are now finally at long last going to have to confront the real choice over Brexit.
"Do they want to leave with a deal, do they want to leave without a deal, or do they want a referendum?"
Labour leader Jeremy Corbyn wants to topple May and win a subsequent election that would enable him to renegotiate the Conservative prime minister's unpopular divorce deal.
However, many of his own Labour MPs and party members want a second referendum that they hope could reverse the UK's decision to leave Europe taken after a plebiscite in 2016.
Tim Bale, professor of politics at Queen Mary University London, said: "The Labour leadership did not put forward this motion because they thought it could get them a general election, they did it because they want to avoid having to endorse a second referendum."
The result of Wednesday's no-confidence vote - May won by 325 votes to 306 - was expected, given the parliamentary arithmetic: her minority administration has survived since an election in 2017 with the support of Northern Irish MPs. She defeated a no-confidence motion within her own party in December.
Even though many Conservative MPs hate the prime minister's Brexit deal - rejected on Tuesday in the so-called "meaningful vote" by a thumping majority - they rallied around her out of hostility to Corbyn.
Labour can call such no-confidence motions again - some of its MPs now see this as a viable strategy - but the latest result effectively rules out a general election for now.
Menon said that Labour figures have made contradictory statements about what to do next, with some calling for recurrent confidence motions until they get the result they want, but others insisting this is pointless.
"There is obviously a real fight going on within the Labour Party about this, and no one knows which way it will go."
Temporary respite
Wednesday's victory will give May temporary respite as she attempts to convince EU leaders to offer sufficient concessions to convince a majority of MPs to back her Brexit deal.
Maddy Thimont Jack, a researcher at the Institute for Government in London, said: "The vote will show that she does have the confidence of the House of Commons, so it gives her a bit more flexibility going into the next step - when she has to bring back the motion [on her Brexit deal] next week with the government's plan B following Tuesday's defeat.
"In the immediate term, it might strengthen her, but it doesn't stop another motion being brought in three weeks' time and - given how fast things are moving and that the clock is ticking - it could then be a very different situation."
However, the implications of Corbyn's decision to move a motion of confidence could be greater for Labour, by prising open its own Brexit divisions - and May knows it, effectively daring Corbyn to challenge her.
Bale said: "She thinks clearly that it is a way of getting the troops to rally round her after Tuesday's terrible defeat, which it is - and it also then exposes the tensions within the Labour Party because it puts the ball in Corbyn's court as regards a second referendum and what to do next?
"He has marched his troops to the top of the hill and he can't really march them down again now."
Second referendum?
Corbyn and other senior Labour figures have used the hope of an election to conceal from their members the fact that they want to proceed with Brexit and oppose a second referendum.
Bale said: "This vote was really not about defeating the government because they know in their hearts that can't possibly be done.
"The confidence motion is something they have been able to hide behind since the Labour Party conference in the autumn, and it allows them to tell their supporters in the country and especially their grassroots members that there is no need for a second referendum yet because they might be able to engineer a general election.
"That was always a fiction and it will be exposed as such - but it might be something that they carry on trying to do for two or three weeks, meanwhile running down the clock."
While Labour is now likely to edge closer to resolving its own policy disagreements, this does not automatically mean it will embrace a second referendum.
Bale said: "It looks as if the leadership is reluctant to do that and is intent instead on pursuing the possibility of some kind of 'softer' Brexit in coordination with the government, or indeed tabling another confidence motion in a few days' or weeks' time."
Menon also noted that a recent gathering of Labour MPs who want a "people's vote" attracted just 71 parliamentarians.
"That isn't very many," he said. "There are an awful lot of Labour MPs who don't want a referendum."
In principle, it would not be difficult to secure parliament's commitment to a second referendum through a motion.
However, it would then require complex legislation and an extension of the March 29 deadline under Article 50 by which the UK formally announced its intention to quit the EU.