Campbell said: ''It would be easy to blame the fact we were unsettled because of our World Cup guys coming back but Llanelli managed to cope with the same situation.
''We were badly outplayed in the set-piece and rugby is a hugely difficult game to play when you don't have the ball.''
Glasgow's Kenny Sinclair and Jon Steel couldn't help Ayr to a victory over Glasgow Hawks at Millbrae. Hawks ran out 18-5 winners to stay at the head of the BT Scotland Premier title race.
Andy Wilson and Dave Millard helped Aberdeen GSFP to a 16-13 win over Currie at Malleny Park. The Dons' only try came from Millard after good work from Rod Seib.