It was relief more than real jubilation. The simple truth was that the combined list of candidates headed by Prime Minister Benjamin Netanyahu had performed disappointingly.
But politics is about expectations.
At one point a rumour swept the gathering that he'd lost more than a third of his alliance's seats in the Knesset - in the end the exit polls suggested it would be more like a quarter. Cue wild celebration.
If you add together Mr Netanyahu's natural allies among the religious parties and the rest of the right - and assume he'll be able to attract at least one party from the centre or even the left - then he should be able to form a government again.
Senior Likud figure Danny Danon was quick to tell me that the only thing that would be remembered from this night was the fact that his boss had won a third term as prime minister.
"There is only one prime minister possible for Israel from these results. And that's Benjamin Netanyahu.
"I say to my friends here on the left that they should not be opening the champagne after these results."
Any champagne that Mr Netanyahu may be tempted to open will be feeling a little flat though.
He emerges from these elections a rather diminished figure, whose wheeling and dealing skills may be sorely tested as he sets about building a new coalition.
When he spoke to a crowd of activists in Tel Aviv he was measured, although it took him some time to persuade his supporters to stop celebrating long enough to make himself heard.
"I am going to seek as broad a government as possible", he said. " I'm going to seek out many partners."
That was perhaps his way of acknowledging that the overall results of the night were curiously ambiguous.
To the left of Mr Netanyahu, Labour picked up seats but to the right of him so did Habayit Hayehudi (Jewish Home party) led by his former chief of staff Naftali Bennett.
The undoubted star of the evening was Yair Lapid, a famous TV presenter who stepped off the screen to found a new centrist party called Yesh Atid (There is a Future).
It has been an extraordinary debut. The party may well emerge as the second largest grouping in the new Knesset and should command a place in a Netanyahu-led coalition.
Because Mr Lapid is a political newcomer, it's hard to say what price he might try to extract in return for his support.
But you can expect a higher profile for the vexed issue of whether Israel's ultra-Orthodox community ought to be required to perform its share of national service (it's currently exempt).
The wider world will examine these results for clues about Israel's future attitude towards peace talks with the Palestinians or the possibility of a pre-emptive strike on Iran's nuclear facilities.
The truth of the matter is that it's far too early to make those kind of judgements, which will depend on the balance of forces within a future coalition more than on the outcome of the popular vote.
But the sudden and decisive lurch to the right that many predicted hasn't happened.
The results show that there's plenty of life on the left and the centre of Israeli politics too.
Some political journalists at Likud headquarters were arguing within hours of the exit polls that the results sent such a confused signal about the political mood in Israel that they made another election likely within a year.
We'll see.
Having said this is a chastening result for Benjamin Netanyahu it's only fair to record that it's been a thought provoking one for anyone in the business of making political predictions here, too.
Mr Netanyahu was supposed to win easily - and he certainly didn't.
And the campaign was supposed to have failed to capture the Israeli imagination - and turnout was remarkably high.
It's said to take an average of well over a month to form a coalition government after polling day here - and there's no reason to assume that it will be any quicker than the average this time around.
The first contacts between party leaders were probably under way before the celebrations at Likud HQ had died away.
Israel and the wider Middle East must now wait to see what sort of government will eventually emerge.
When the giant TV screens at the Likud election headquarters finally flashed up the results of the national exit polls, one-by-one there was a sudden tidal wave of sound.