David Trimble has retained his leadership of the Ulster Unionist Party - but by a narrower margin than had been expected.
He beat South Belfast MP the Rev Martin Smyth by polling 457 votes to 348.
Mr Smyth's share of the vote, 43 per cent, was considerably above the level that was considered to be potentially damaging to Mr Trimble prior to the vote.
There were loud cheers from within the King's Hall, Belfast as the result was announced, along with calls for Mr Trimble to resign which were later described by Young Unionist Timothy Johnson as "loud and widespread".
He said the closeness of the vote clearly surprised Mr Trimble and his supporters, describing an "atmosphere of stunnedness" among them.
He said that Mr Smyth's supporters were buoyed up by the result and predicted they would be able to "secure a new leader" through a fresh leadership challenge in the near future.
Trimble ally Michael McGimpsey, a former Stormont minister, said there was no question of a resignation and the issue was now closed.
"Yes there is a split within the party, but there is also a clear majority for the leader and his policies. That means rock solid.
"Certainly we would have liked it to have been much more comfortable, but this is a period of extreme tension, nerves and worry for the party and there would have been an element of protest votes in there."
The narrowness of the victory is being seen as a severe blow to Mr Trimble's leadership, damaging his credibility as a leader of Ulster's unionist community.
The vote has implications for the Northern Ireland peace process as Mr Trimble needed to retain the confidence of his party in order to re-enter negotiations with Sinn Fein over decommissioning.
This afternoon, Mr Trimble will face an equally crucial motion from London-based businessman David Burnside, who wants retention of the RUC's title to be linked directly to any possible deal to re-start the suspended political institutions.