Reigning champions Munster look well set for the knockout stages after defeating a spirited Aberavon side.
Captain Sean Dougall, part of a superb back-row, was content to have negotiated a potential minefield and preserve their four-point lead at the top of the table.
"It was a dogfight but we dug in and took our chances when it mattered, but we were not ruthless enough," he said.
"Playing in Wales is never easy. We expected a tough crowd and got one."
In the first half, a slick backline move cut open the hosts to allow Ronan O'Mahony to canter over. JJ Hanrahan added the extras and a penalty to send Munster into the break 10-3 up.
Munster started the second half at a frenetic pace. Danny Barnes seared over, and Hanrahan added a penalty.
Aberavon, aided by a dubious CJ Stander yellow card, fought back with a try and two penalties, but Munster weathered a late storm.
Aberavon RFC – P Bamsey; R Carter, R Thomas, W Price, R Thomas; C Evans, J Heatley; N White (J Tomlin-Reeves 69), G Harvey (E Yardley 61), A Clatworthy; G Ronan (R Morris 59), S Williams (capt); B Thomas (L Purnell 40), N Strong (R Jenkins 65), C Davies.
Munster 'A' – D Hurley; D Barnes, S Deasy, I Dineen, R O'Mahony; JJ Hanrahan (J Holland 78), C Sheridan; J Cronin, D Casey (N Scannel 64), A Cotter (C Condon 56); D Foley (B Hayes 56), I Nagle; Dave O'Callaghan (R Murphy 70), S Dougall, CJ Stander.
Ref – R Campbell (England).