Celtic took control of their second qualifying round Champions League tie against Linfield with a 2-0 win in Belfast on Friday.
Scott Sinclair headed home from a James Forrest cross early on and Tommy Rogic added a quick-fire second to put the visitors in command.
Celtic created few chances in the second half, the best of them falling to Stuart Armstrong from a neat Moussa Dembele knockdown, as Brendan Rodgers' side held off their hosts with little difficulty.
The Scottish champions have one foot in a possible third-round qualifying tie against Ireland's Dundalk ahead of next Wednesday's second leg at Celtic Park.
Celtic dominated possession from the off against the part-timers and went close early on through Kieran Tierney and Stewart Armstrong who tried their luck from distance.
The breakthrough came when Forrest recovered the ball from an Armstrong corner and crossed for Sinclair to plant a soft header beyond the flat-footed Roy Carroll in the Linfield goal.
And five minutes later it was 2-0, Rogic showing intelligent movement to lose his marker and manoeuvre space to finish with a low shot past Carroll after a drilled corner from Griffiths.
Linfield were dogged in their defending and limited Celtic to shots from distance, with Forrest going closest for the visitors with a low strike on the angle which Carroll gathered at the near post.
Substitute Dembele set up Armstrong for a fizzing drive in the second half beaten away by Carroll, and Mikael Lustig showed consistent endeavour to get forward from right-back, overlapping well with substitute Jonny Hayes, who impressed on his debut after signing from Aberdeen.
Dembele went close to adding a third for Celtic with a low curler which was well saved, but Rodgers had to settle for a 2-0 win to take back to Parkhead for the right to play Dundalk or Norwegian side Rosenberg.