Ulster Ravens lost their grip on an early 11-3 lead as two tries from number 8 Rob Dudley-Jones inspired Aberavon to an 18-14 comeback win in Pool 2 of the British & Irish Cup.
The Wizards battled their way to a hard-earned victory at the Talbot Athletic Ground despite having three players sin-binned over the 80 minutes and suffered a series of injuries.
Ulster Ravens were left to rue their failure to build on a promising first half performance which included a try from summer signing Ruaidhri Murphy and two Sean O'Hagan penalties.
The Ravens will aim to bounce back when they entertain Yorkshire Carnegie at Kingspan Stadium next Saturday (kick-off 2pm). Match tickets can be bought here. Carnegie lost their opening game to Rotherham Titans (20-3).
The opening 40 minutes in Port Talbot were dominated by referee Matthew O'Grady's whistle who awarded a high number of penalties – not many of which were in kicking range.
Out-half Ceiron Thomas' second-minute penalty opened the scoring for Aberavon, but the Ravens were level within four minutes thanks to a good strike from Ireland Under-19 international O'Hagan.
The Ulster youngsters gained the upper hand as the hosts' discipline began to let them down and they lost two backs to the sin-bin in quick succession – winger Stef Andrews was followed by centre Joe Gage, with O'Hagan sandwiching his second penalty in between.
Even better followed for the Ravens as they took advantage of the two absentees to work prop Murphy over for an unconverted try in the 20th minute.
They deserved their 11-3 lead given their greater control of possession and while attacking breaks were rare, one notable surge from centre Ricky Andrew showed what the province were capable of.
However, they were unable to add to their tally approaching half-time and resilient Aberavon hit back with a forwards-initiated try from Dudley-Jones which Thomas converted for 11-10.
Referee O'Grady had his yellow card out again just a minute into the second period, binning Aberavon prop Neil White, but again Ulster failed to make full use of their numerical advantage.
Aberavon turned defence into attack and a clever switch from Thomas created space for the lurking Dudley-Jones out wide and he carried the final 20 metres to crash over in the left corner.
Thomas tagged on a penalty to push the lead out to 18-11, although replacement Josh Bingham answered back in the 53rd minute for the Ravens who appeared to be building for a strong finish.
The Ulster side's efforts were foiled though by some hugely committed defending from the Wizards, who put their bodies on the line against the visitors' advancing pack.
Thomas missed a penalty in the 78th minute but gritty Aberavon held on to win by four points and gain revenge for the 62-0 hammering the Ravens served up in Belfast in March 2010.
Referee: Matthew O'Grady (England)