Outhalf Paddy Wallace kept Ulster's Celtic League hopes alive with an immaculate kicking performance to keep the province on course for a quarter-final place after a hard-fought win at Eugene Cross Park.
Wallace, in the starting line-up for the first time for first choice David Humphreys, ended the game with 19 points from the boot and only missed one kick all night.
The 21 year old slotted over two conversions and five penalties to give Ulster a win they had looked unlikely to grind out at half-time.
They were made to fight all the way and only a second-half fight back saved their blushes against a side regarded as one of the weakest in the top flight in Wales.
At the break Ulster trailed 20-3 after failing to break down a well-marshalled and dogged home side.
Full back Gareth Cull landed his side's first penalty before being taken off with a shoulder injury before Wallace slotted over his first penalty.
Wallace's opposite number, Scott Mitchell, who took over the kicking duties from the injured Cull, landed a touchline penalty to put the Welsh side back ahead.
Ebbw Vale then had Tongan flanker Kati Tuipolotu sinbinned for lying on the ball when wing Tyrone Howe was held up just short of the line. But despite being down to 14-men Ebbw Vale didn't buckle and took advantage of some sloppy Ulster defence for a well-worked try after Ireland and Lions lock Jeremy Davidson lost a line-out.
The Welsh side caught the Ulster defence napping and spread the ball wide and big wing Andrew Wagstaff crashed in at the corner, with Mitchell converting.
Things went from bad to worse for the Ulstermen with Gareth Betts, the Ebbw Vale scrum half, leaving the defence flat-footed with a sniping run from the base of a ruck to score under the posts. Mitchell added the conversion.
After the break it was all Ulster, with Wallace adding two quick penalties. Centre Ryan Constable latched onto a loose ball for an easy run in to the line, converted by Wallace, followed by two more penalties from the outhalf to give Ulster the lead for the first time.
Howe then sealed the victory with a late try before Ebbw Vale scored a consolation score deep into injury time by replacement flanker Gareth Green.
EBBW VALE: G Cull ( P Matthews 9); A Tarangi, R Shorney (K Eliss 72), D Weatherley, A Wagstaff (N McKim 33); S Mitchell, G Betts; I Thomas, L Phillips (J Evans 65), M Jones, C Billen (capt), N Edwards (P Sidoli 65), K Tuipolotu (G Green 65), W Thomas, P Williams.
ULSTER: N Malone (B Cunningham 71); J Topping, R Constable (S Stewart 56), A Larkin, T Howe; P Wallace, N Doak; J Fitzpatrick, P Shields, M Blair ( G Longwell 53), J Davidson, D Allen, A Ward (capt), R Nelson.
Referee: T Spreadbury (England)
