London Welsh had to withstand a second-half Plymouth Albion onslaught before bagging their third away win of the season on Saturday.
Welsh blitzed Albion with three first-half tries, with Tom Brown finishing off Paul Sampson's inside pass and Sunia Koto Vuli being driven over, before Welsh were awarded a penalty try following a succession of scrums on the Albion line.
Thomas converted twice, but Albion grabbed a try back before the break to pull it back to 19-7.
Another try and a penalty after the break brought Albion to within three points. But a Thomas penalty and a Hugo Ellis drop-goal settled Welsh nerves. That was until another Albion try eight minutes into injury time, but fortunately the conversion was accompanied by the final whistle.